The best use that i have found for Twitter is that many, many experts in my industry post useful information and resources to Twitter that they don't post to their regular content outlets (like their blogs). I have found a lot of good info from people this way. It's simple for them to quickly blast out a useful link instead of having to construct an entire blog post around something they like or find useful.
Same with me...if I find a good piece of info I can share it quickly instead of needing to concern myself with creating and maintaining a full-blown blog.