You’ve seen it on the street. In coffee shops. At the grocery store. People frantically thumb-typing on their phones about something. Or someone. Or nothing… All in 140 characters or less. It’s the Twitter.

So what is it, you might ask? Here is a simple explanation from Twitter: ”Twitter is a service for friends, family, and coworkers to communicate and stay connected through the exchange of quick, frequent answers to one simple question: What are you doing?”

Here’s what my wife said when I tried that explanation on her.

“What are you doing? Who cares what you are doing?”

I was doing a better job of convincing her that Twitter is a complete waste of time than explaining what an extremely powerful social media tool it is. So I told her, ”The President does it.” Seems as good an example as any, I thought. “And it helped get him elected.”

While on the campaign trail almost two years ago, then-Sen. Barack Obama first Tweeted, “Thinking we’re only one signature away from ending the war in Iraq.” 3:04 PM Apr 29th, 2007. He was at 500,000 followers a month ago, is at 900,000 now, and will probably have passed a million before this post is up.

“Oh, when are you planning on running?” My wife asked. Did you pick up on the sarcasm? She was laying it on pretty thick.

Next, I tried to show her how Twitter works for the common good by telling her how the Boston police used Twitter this year to communicate during the city’s notoriously awesome St. Patrick’s Day parade. ”One goal is to interact in real time with the public during festivals and large-scale events,” the Beantown heat said.

“Will you be making citizen arrests?” she taunted.

But there’s no denying its utility and popularity. Most twitterers simply update their status. Others might include a link to a recent inspiration. Some are using Twitter on a whole different level. Kogi bbq - Korean BBQ To-Go, is a food cart in LA that uses Twitter to tell followers where the cart is in real time. Kogi’s tweets not only lets followers know where lunch is that day, but also puts Kogi bbq in your mind before heading out to lunch. Hmm… bbq pork sounds good. Another is NY’s City Bakery which tweets to let you know fresh batches of cookies are out of the oven.

Another good use of Twitter is to get advice by asking questions of everyone and no one in particular. Twitter is great for getting opinions.

Still not grasping how Twitter can benefit you? See how the folks at Common Craft explain it in this video.

Not only is Twitter as fun and addicting as other social media sites like Facebook and the Myspace. Twitter has turned into a great way to keep tabs on what your industry and customers are doing. Companies are using Twitter to gain credibility in their industry, increase their audience, and potentially attract new business.

As a Web developer here at Vital Design, I am constantly watching what is bringing our site traffic. Our client base is primarily in a 2-hour radius from Portsmouth, NH, including Boston, Worcester, MA and Maine. After dabbling in social media for a short time, our site’s top four referral traffic sources became Google, Twitter, Linked In, and Facebook. A statistic that speaks for itself as far as I’m concerned. Having the power to send people to your website through your own involvement in social networking sites is big, especially for a regional company like us.

Founded by Jack Dorsey, Evan Williams, Noah Glass, and Biz Stone, Twitter has been steadily picking up steam since it’s release in March 2006. A February 2009 Compete.com blog entry ranks Twitter as the third largest social network, and puts the number of users at roughly 6 million and the number of monthly visitors at 55 million. Twitter grew 752% in 2008, not bad.

I think I’m going to Tweet about this blog… we’ll see what happens, follow me on twitter to find out.

And of course, follow Vital Design on Twitter.