Taskboard
Taskboard is an agile project management tool for distributed teams.
There are two versions: a free taskboard for individual use and small teams and the enterprise taskboard which also unlimited tasks, projects, and users.
It is a rich internet application (RIA) build using Adobe Flex. It currently uses AMFPHP for fast server-side communication, but we're upgrading it to use Live Cycle Data Services (LCDS) to offer more features, including real time messaging and automatic data synchronization.
We're also working on an Adobe AIR version, and may port it to use AJAX if there's a demand. Another cool application with a similar featureset is Scrumy.
Taskboard can also be integrated with your QA Site.