Quakk is an Open Source Windows Mobile Twitter Application
You can download the Quakk application using the big link below. Alternatively, you can track any updates and progress at the Quakk section of my blog; or if it's the source code you're after, you can get your greedy mitts on it at CodePlex.
Want to keep an eye out for updates or complain about errors? Follow us: @quakkquakk