I think gitfiddle would be a great name for a service that let you quickly share unnamed, temporary git repositories, showing them to other people, then taking them down, without the friction of GitHub.
Like a git pastebin. In fact, I think gitbin would be better. gitfiddle should be a service where you could do all this, but would also offer ways of messing with the repository (doing interactive rebases, for example) from the web interface.
