I came across a nice comparison of the three distributed version control systems out there. I’m currently using mercurial in parallel with subversion for one of my projects, just to try to grok it. I don’t do a lot of branching (none, really) so the comparatively nasty way it’s handled by mercurial relative to git (which I used for a while) hasn’t bitten me, but based on the linked article (by an author who also picked mercurial), I may be returning to git in six months or so.