I've settled into a pretty happy workflow using Git as a local snapshot of an upstream Subversion repository using git-svn. With a bit of discipline, you can keep things nicely in sync, and get the benefits of cheap-as-hell branching and local/offline commits without forcing your entire project team to migrate to a new VCS.

I've got some notes on the subject on my blog:

http://rcoder.net/content/daily-git-svn