Try this app.
ceTwit - This app uses the .net compact framework. It features timeline display (both merged and filtered), account storage (it remembers you every time!), status updates, direct messages, click to reply, auto refresh, avatars in timeline (with local caching), relative timestamps, follow/unfollow, Twitpic support, ping.fm support, audible/vibrate alerts, and retweeting. This is the
Twitter client that I use on my phone because I use
Twitpic and
Ping.fm often. I also love the user interface of this app - very quick and easy to use.