this is a fab post Eliz, about how to track conversations by people who you follow or topics - see hashtags bookmark. This is possible through the tools on the page.
What goes with some of the tracking tools & stragegies mentioned would be the lovely ow.ly which allows mutliple users to use one twiter account, and the scheduling of tweets. Also tweetdeck is another good customisable application to monitor the tweeter stream ;-)