I have a Mercurial repository for a personal project, and I have been storing the master repository in my Dropbox for a few weeks now (something along this line; and I under
I've had problems with my Dropbox'ed repositories becoming corrupted. It doesn't happen all the time, but the fact that it has happened more than once means that I'm going to stop using Dropbox for this purpose.
That said, Dropbox is certainly cheaper than getting real hosting, so as long as you keep backups you may find it acceptable for personal projects.