We at TUAW HQ definitely have an obsession with Twitter. We use Twitterrific for the Mac, and Hahlo for iPhone. Hahlo provides great features in a beautiful, usable user interface. A couple weeks ago we got a sneak peek at the beta of Hahlo 3 (titled "the Legendary Edition"), but now you can try it out for yourself. That's because Hahlo 3 was released to the public today. In addition to a completely revamped UI, the new version integrates full searching capabilities via Summize.
To try out Hahlo 3 for yourself, just point Mobile Safari over to http://hahlo.com. It's free and easy to use. If you don't have an iPod touch or iPhone, you can get to Hahlo from any standards-compliant modern browser (Safari 3, Firefox, etc.).