Update: uTweeteMe has been updated to version 1.3 alpha. Because of changes Twitter made to the login process (OAuth is now required) the previous version no longer works and you have to update to continue sing uTweeteMe. There's been a small enhancement. You can now view @Replies to you on their own page.
I've received a few requests for a better Twitter client than TinyTwitter. I just sent an hour looking at a bunch of them and frankly they are all pretty bleak. The best of the bunch seems to be uTweetMe.
It's fast, all keys are mapped correctly and it's fairly full featured. You can view your Friends Timeline, Tweet, Retweet, Reply, send DMs, view @Replies and view sent and received DMs. There are templates if you are into Tweeting the same canned text over and over. Unfinished Tweets can be saved as drafts. On the other hand there are a lot of things missing; you can't see Avatars or Twitpics or follow people. And words are split across lines rather than wrapping properly. You can't follow links in Tweets either, although this is a limitation of the iDEN Java run-time rather than UTweetMe.
The other Twittter clients I tried and rejected are:
Twitlet: limited feature set and ugly full justified timeline display.
Jitter: TinyTwitter with ads.
Twibble, Twim: Failed to connect.
If anyone knows of a better Java Twitter client please let me know in a comment. For now, the best way to do Twitter on iDEN phones is Opera Mini combined with a good Web client like Tweete.net or Dabr.co.uk
Vendor: uTweetme - Product Page
Data Connection Required: Yes
Supported iDEN phones: All Falcon Series (i776, i465, i9, i290, etc.)