Accessible Twitter works just like Twitter with a few interface tweaks. Upon visiting the site, the first thing one notices is the large default text size and the high color contrast. The layout is simplified and consistent, with keyboard-accessible links and clean markup.
I tested the application with JAWS and a screen-reader emulator, and I found both experiences to be reasonably straightforward and barrier-free. Accessible Twitter is currently in the alpha stage, with direct messaging and replying features complete. Still to come are active hyperlinking, pagination and follower/followee viewing.