If you don't like using native apps for Twitter on your smartphone, Twitter has just released today a new mobile version of twitter.com to a small percentage of users on the iPhone, iPod Touch, and Android smartphones.
According to the Twitter Blog:
The app is fast – you can quickly scroll through your timeline, move between tabs and compose Tweets. It’s rich – it takes advantage of capabilities that high-end device browsers offer, such as touch gestures and a large screen. And it’s simple – it’s easy-to-use and has the features you’d expect from a Twitter application, including your timeline, @mentions, messages that you can read in conversation view, search, trending topics, lists, and more.