An artist in Oakland, California is using his skills to help the homeless. Greg Kloehn builds very small shelters that make life on the streets a little more comfortable. The structures offer the homeless some safety and protection from bad weather. Each little house also has wheels on the bottom so it can go wherever its owner goes.

    Greg Kloehn has given away at least 20 tiny houses. Several are on the roadside near an active railroad. On a recent day, Mr. Kloehn stops at one to visit Oscar Young. The two men hug. Inside his little shelter Mr. Young gets relief from cold nights on the streets. Mr. Kloehn also visits Sweet-Pea, another friend who also lives in one of the little homes the artist built. She says it keeps her safe and protects her belongings.

    In the mornings, Mr. Kloehn searches the streets for building materials. He gathers what he can and takes it to his studio. There, he puts the houses together. Empty coffee bags become roof material. A washing machine door and refrigerator part become windows. Nails, screws and the sticky glue hold all the pieces together. The artist also attaches a small electrical device to the house. The device is powered by the sun.

    Some of the people living on the streets once had normal houses of their own. But some of the people say they have learned to live with less and they are thankful to that man.

    Mr. Kloehn says his work is not a social project. He says he is just someone using his skills to help his homeless neighbors.

    Today, I made the time to listen to a person new to me, who I met was parking my car, “Perfect”, he said as he walked by me as I checked how considerately I parked. He was a clean cut gentleman sharing his feelings about his grown kids, parenting mistakes he is aware of, while expressing a realization to slay clear of destructive addictions.

    I listened patiently and kindly. He seemed quite comfortable with me, in need of some treatment letting go of his thoughts and emotions. After talking for a while, I had to go inside, and I asked him to wait on the sidewalk and I'd be right back with some gifts for him. He was so receptive all along, and I could feel the desires of his heart. I returned to him with bookmarks. I encouraged him, also, with a couple of inspirational thoughts to live by: To focus on what you want — how you want to feel and how you want to live and experience life.

    This experience is a good thing to me, meeting this gentleman as I am experiencing the challenges of trying to be a positive encouragement to my daughter Angel in fighting her illness. I know Angel has the desire too, although in a different way and at a different level in her growth.

    I've received little to no reaction from Angel about the positive encouragement of the family. On the other hand, this gentleman paid attention. Some of this, of course, is the big age difference, I imagine. Anyhow, I extended myself in friendship to have a walk and talk with my daughter early tomorrow morning, so as to be a curing support, and it feels good for me, too — although far outside my usual comfort zone.

    Outside, it's a cold winter's day. Inside a large shopping center, people are hanging around. But then, without warning, a pop song starts to play loudly. A teenager boy walks lazily to the center of the open space, and dances crazily to the music. He's joined by two of his friends, then some of the old people. Within the space of a few seconds, more than sixty people are dancing to the music - all in time and all in step. At first, onlookers are baffled, then they start smiling and clapping. They now know what they're seeing: a flash mob （快闪）.

    According to Wikipedia, the term "flash mob" was created by Bill Wasik, an editor at Harper's Magazine, in 2003. Within a year, the phrase had entered the Concise Oxford English Dictionary. Since then, hundreds - possibly thousands - of flash mobs have been carried out around the world, in almost every kind of public space imaginable!

    Each flash mob has its own style, but most flash mobs follow a similar formula （方案）. Often, the organizers search for willing participants using social media. Instructions and dance moves are given through email or video download. There are usually several rehearsals （排练） before the big day.

    While it's happening, a few lucky passers-by watch it live. Most people who watch it, however, will see it later online. Some of the most popular flash mobs on YouTube have been watched more than 10million times. A famous example is MP3Experiment Eight, a flash mob that took place in New York City in July 2011 with over 3,500 participants. This event differed from normal flash mobs in that much of it was completely silent - and there were no rehearsals.

    Flash mobs provide the participants, onlookers and online viewers with a lot of enjoyment and pleasure. For this reason alone, they're a modern, popular art form that should be celebrated.

    The first organized system for sending messages began in Egypt around 1500 B.C. This system developed because the pharaohs frequently needed to send messages up and down the Nile River in order to keep their empire running smoothly. Later, the Persians developed a more efficient system for sending messages using men and horses. Messages carriers rode along the road system stretching from one end of the Persian Empire to the other. Along these roads, fresh men and horses waited at special stations to take and pass along any messages that needed to be sent. The stations where riders passed messages back and forth were built 23 kilometers apart, so the men and horses were able to travel quickly between them. The Romans later took up his idea and improved it by using a more advanced and extensive road system.

    In China, however, Kublai Khan had built up his own system for delivering messages. This system worked in the same basic way as the Roman system. The difference was that Kublai Khan kept 300,000 horses along the roads of this delivery lines. There were over 10,000 stations where a message would be passed from one rider to another with a fresh horse. In this way, Kublai Khan could receive messages from anywhere in the country in only a few days.

    It was not until the 1500s that a well-organized postal system appeared again in Europe. One family, the von Taxis family, gained the right to deliver mail for the Holy Roman Empire and parts of Spain. This family continued to carry mail, both government and private, throughout Europe for almost 300 years.

    In 1653, a Frenchman, Renouard de Velayer, established a system for delivering post in Paris. Postal charges at that time were paid by the recipient, but de Velayer's system was unique by allowing the sender to pre-pay the charges, in a similar way to the modern stamp. Unfortunately, de Velayer's system came to an end when jealous competitors put live mice in his letter boxes, ruining his business. Eventually, government-controlled postal systems took over from private postal businesses, and by the 1700s government ownership of most postal systems in Europe was an accepted fact of life.

    The thing that all these early systems had in common was that they were quite expensive for public use, and were intended for use by the government and the wealthy. However, in 1840, a British schoolteacher named Roland Hill suggested introducing postage stamps, and a postal rate based on weight. This resulted in lowering postal rates, encouraging more people to use the system to stay in touch with each other, His idea helped the British postal system begin to earn profits as early as 1850. Soon after that many other countries took up Mr. Hill's idea. And letter writing became accessible to anyone who could write. Today, the Roland Hill awards are given each year to "encourage and reward fresh ideas which help promote philately"(stamp collecting).

    As data and identity theft becomes more and more common, the market is growing for biometric(生物测量)technologies—like fingerprint scans—to keep others out of private e-spaces. At present, these technologies are still expensive, though.

    Researchers from Georgia Tech say that they have come up with a low-cost device(装置)that gets around this problem: a smart keyboard. This smart keyboard precisely measures the cadence(节奏)with which one types and the pressure fingers apply to each key. The keyboard could offer a strong layer of security by analyzing things like the force of a user's typing and the time between key presses. These patterns are unique to each person. Thus, the keyboard can determine people's identities, and by extension, whether they should be given access to the computer it's connected to—regardless of whether someone gets the password right.

    It also doesn't require a new type of technology that people aren't already familiar with. Everybody uses a keyboard and everybody types differently.

    In a study describing the technology, the researchers had 100 volunteers type the word "touch" four times using the smart keyboard. Data collected from the device could be used to recognize different participants based on how they typed, with very low error rates. The researchers say that the keyboard should be pretty straightforward to commercialize and is mostly made of inexpensive, plastic-like parts. The team hopes to make it to market in the near future.

    I prefer Lynne Truss's phraseology: I am a grammar "sticker". And, like Truss—author of Eats, shoots & Leaves – I have a "zero tolerance" approach to grammar mistakes that make people look stupid.

    Now, Truss and I disagree on what it means to have "zero tolerance". She thinks that people who mix up basic grammar "deserve to be struck by lightning, hacked (砍) up on the spot and buried in an unmarked grave", while I just think they deserve to be passed over for a job—even if they are otherwise qualified for the position.

    Everyone who applies for a position at either of my companies, iFixit or Dozuki, takes a compulsory grammar test. If job hopefuls can't distinguish between "to" and "too", their applications go into the bin.

    Of course, we write for a living. iFixit.com is the world's largest online repair manual (指南), and Dozuki helps companies write their own technical documentation, like paperless work instructions and step-by-step user manuals. So, it makes sense that we've made a strong strike against grammar errors.

    But grammar is relevant for all companies. Yes, language is constantly changing, but that doesn't make grammar unimportant. Good grammar is credibility, especially on the Internet. And, for better or worse, people judge you if you can't tell the difference between "their" "there" and "they're".

    Good grammar makes good business sense—and not just when it comes to hiring writers. Writing isn't in the official job description of most people in our office. Still, we give our grammar test to everybody, including our salespeople, our operations staff, and our programmers.

    Grammar signifies more than just a person's ability to remember high school English. I've found that people who make fewer mistakes on a grammar test also make fewer mistakes when they are doing something completely unrelated to writing—like stocking shelves or labeling parts. It is the same with programmers. Applicants who don't think writing is important are likely to think lots of other things also aren't important.