In case you haven't tried any of these sites out, I'd highly recommend you take a look. This is for anyone who is relatively new to social media, microblogging, and socnets (social networks) in general and hasn't yet heard about twitter and the amazing things you can do/learn from the twitterverse.
1. Twitter - the center of the interwebs. http://twitter.com
2. Friendfeed - the latest uber-socnet aggregator. http://friendfeed.com
3. Quotably - new site that allows you to better track twitter conversations. http://quotably.com
That's all for now.