One of the big disadvantages that GitHub has over for instance Gitorious is that there is no way to clone a repository over HTTP. The service is currently limited to cloning via git:// which is quite a problem if you’re living behind for instance a corporate firewall.
There already is a ticket associated with this problem on GitHub’s Lighthouseapp project page, where defunct wrote:
I’m going to close this until more people ask for it. We plan to start keep track of clone stats so git-daemon is actually preferable.
So please everyone, vote for this ticket.