Q: What’s the newest and fastest growing microblogging phenomenon to hit the Internet in the past year?

A: Twitter.

Simple in concept and design, Twitter allows you to send twitters, or messages, to all of the twitterers following your account. It’s an online global community that asks its users to answer one question—“What are you doing?”—in 140 characters or less. But it can also be a great asset when launching your book media tour.

Twitter combines blogging, text messaging, and instant messaging on a platform that allows you to send real-time messages to thousands of people worldwide.

Why not send messages about your upcoming TV or radio interviews? You can twitter about the release of your book, your website, or what you had for lunch. Twitters are not necessarily sent to elicit response, but to let the world know what you are doing at the exact moment you are doing it.

After winning the top award at the South by Southwest Interactive Festival in March, Twitter saw an increase of 50,000 users in one day. According to the San Francisco Chronicle, Twitter is steadily growing at a rate of 20 percent a week.

2008 presidential candidate John Edwards twitters about his campaign travels, and according to the New York Times, may have been the first major candidate to make a policy clarification on a social medium. Presidential campaign managers have realized the impact and reach of social media; take their lead and make it work for you and your book.

Give Twitter a test drive and check out TwitterVision. TwitterVision shows your up-to-the-minute twitters from around the world and pinpoints their origins. Be one of the first authors to twitter about your book tour by signing up for a free account at Twitter.com.

In the next social media guide: It’s time to hop on the bandwagon and join the millions of people who have taken advantage of two little social phenomena know as MySpace and Facebook. You may have heard of them.