My current project is Woodchuck Woodchuck (source), a download manager for delay tolerant data, such as blogs, podcasts, and email. By orchestrating when applications transfer data, Woodchuck saves battery power, reduces the impact of data caps and hides spotty network coverage.
I've recently made a release of Woodchuck, including packages for the N900. Currently, I'm working on porting applications to use Woodchuck. So far, I've ported FeedingIt and gPodder. Other packages are in the works.