I think that Git on Dropbox is great. I use it all the time. I have multiple computers (two at home and one at work) on which I use Dropbox as a central bare repository. Since I don’t want to host it on a public service, and I don’t have access to a server that I can always SSH to, Dropbox takes care of this by syncing in the background (very doing so quickly).
Setup is something like this:
~/project $ git init
~/project $ git add .
~/project $ git commit -m "first commit"
~/project $ cd ~/Dropbox/git
~/Dropbox/git $ git init --bare project.git
~/Dropbox/git $ cd ~/project
~/project $ git remote add origin ~/Dropbox/git/project.git
~/project $ git push -u origin master
From there, you can just clone that ~/Dropbox/git/project.git
directory (regardless of whether it belongs to your Dropbox account or is shared across multiple accounts) and do all the normal Git operations—they will be synchronized to all your other machines automatically.
I wrote a blog post “On Version Control” in which I cover the reasoning behind my environment setup. It’s based on my Ruby on Rails development experience, but it can be applied to anything, really.