Twitter has just been updated with some new features… for example, one new feature allows anyone to track concepts in real time over SMS or IM. Tell Twitter what words or phrases you’re interested in and you’ll receive updates containing those words the instant anyone Twitters them. One of the most popular words being tracked by people right now is “overheard.” Send “track overheard” to Twitter to find out why. (Send “untrack” if you change your mind and “stats” to get a list of words you track.) http://twitter.com/blog/2007/09/tracking-twitter.html Or, interested in knowing more about a twitterer… now you can send “whois username” to find out more about that person, or “follow username” to follow his or her updates.