The Android Market has more than 120,000 applications, many of whom intended to Twitter. Here is a brief description of some:
Twitter: This is the official Twitter application, it is excellent and its design is not fully adapted to QVGA, therefore Wildfire HTC among others.
Seesmic: The main advantage is the display of pictures of Twitpic in the application itself (not to redirect the browser) it is rather convenient.
Twidroid: For me, this application is the best Twitter client for Android, its main advantages are speed, clarity, variety of designs available and the availability of many services shortening links, video sharing (Pro Version) and pictures. Two versions are available, a free and a Pro available around 4 €.
Twicca: It’s not bad, but it remains in beta for several months.
You’ll understand, my favorite application is Twidroid, it allows more features and better comfort than many others. An updated version of Free Will made a pub, I’d rather not install it but without advertising, it is really complete.