Twitter is often thought of as a mobile application, but the mobile version of the service that the company itself offers is maddeningly feature-bare. Users can't read replies via m.twitter.com, for example.
If you're looking for a good, full featured way to use Twitter on your phone - you need not look any further than Slandr. Hahlo.com is a close rival if you're on an iPhone, but those iPhone owners get everything fun - don't they? Let's talk about Slandr for the rest of us!
So Much You Can Do
Slandr takes full advantage of the Twitter API, as far as I can tell. You can view replies and direct messages with a link, though not in the timeline as some other clients allow. You can do a Twitter search using the fantastic service Summize, something that Hahlo lets you do on the iPhone as well. You can also edit your location field in Slandr - something I haven't see anyone else do. Then, you can view the locations of the last 20 friends who've tweeted. That has potential. Much of that potential is unrealized, but imagine a combination of Slandr and Twitt
The hard thing about all this cool stuff (for Twitter) is how is anyone going to monetize these little cool apps. does anyone know whether any Twitter app developer has successfully charged for their apps? I'd love for the Twitter ecosystem to work, but don't see how it will (financially).