If you have read my previous piece Twitter Me This: Will You Go Truffle Hunting in the Forest Today? you will know that I quite like the site. It can help a little with Google because all tweets, unless private, appear on searches and people can link to your site from your Twitter account. Above all it can be fun and lead to interesting finds. I know that at first glance it can seem like you made a wrong turning and landed on planet Bebo.
You can read over at O'Reilly how Twitter was almost used in the absence of microphones at a Web 2.0 Expo in San Francisco.
Today I discovered that Twitter can make the earth move. Just go to TwittEarth and experience it for yourself. While there it is easy to forget that your tweets are appearing in the normal timeline. I predict that those in love may find this useful to say good night when apart. You need have a Twitter account to use TwittEarth.