If you need a way to temporarily host a few git projects (for coworking or meetups, perhaps) my company has released a version of our git server preference pane for MacOS 10.5.
It's not intended to be as extensive as Gitosis or Gitorious but is nicely suited if you want to host a project temporarily while working out ideas before pushing a major commit to a repository with more uses. That is, after all, the promise of distributed source control.
Download the source or the compiled preference pane