So you want to know about twitter, huh?  Well, basically twitter, or twittering, is a status update.  You post short (140 characters or less) blurbs, called “tweets” about what you’re doing, what you’re thinking about, how you’re feeling, where you are, what website you’ve recently been to that was “All that and a bag of chips”, new bands you’ve discovered, etc.  The sky (or 140 characters) is the limit, whichever comes first.

Pros:

Twitter has several ways that it can be useful.  It can be a good way to keep up to date on what your friends are up to, especially if that friend lives out of town.  It’s a very connectional service, people can meet people with similar interests, I’ve even heard of people being offered jobs based on the content of the things they post.  These can be updated as often as you like, and can let people know what’s going on in the next few days, or what’s been going on by the minute.  Twitter was used during the presidential debates to maintain second to second updates.  It’s been used at conferences such as Macworld to keep minutes.

Cons:

The danger is that it’s easy to share too much information, namely personal information that would allow random people to indentify you.  As a twitterer your tweets are publicly accessible to anyone with a web browser.  You can block certain users, on an individual basis, from seeing your page, but mostly there are few security features for twitter.

For more information, check out the Twitter FAQ page.