I had the chance to speak w/ Buzz the other day and get a demo of just how cool this program is. I've since added a couple dozen active words to my repertoire and am just amazed at how quickly these shortcuts turn in to habits.
A lot of this discussion has focused on launching but I'm using it a ton for text replacement as well. For example esig, psig, isig, tsig all insert customized signatures in email responses while fsig adds a quick little forum signature like this: