Using the wonderful GS server from mediatemple allows the use of svn & git versioning systems. SVN was really easy to setup as was git, but git has a few issues when trying to push to it in the way that mediatemple suggest.
Since git likes to push back to its 'origin' the best way to do this is to clone from the ssh side rather than the read only http side. If you set up the repo on a subdomain of your site such as git.mt-example.com then you can clone the repo like this (all one line, I just broke it to fit it in):
git clone ssh://firstname.lastname@example.org /home/#####/domains/git.mt-example.com/html/mt-example.git
Once you have that cloned you can then push without having to specify the url.