Bitbucket is Pretty Decent
While it's no GitHub, I've been working with Bitbucket for a few projects with a friend, and I have to say it's not bad at all. I happen to like the helpful hints GitHub offers on making a new repo, but the help Bitbucket has is very fair, and reasonable. It's got a little different UI, which is fine, and it works pretty much the same so that you don't have to come up to speed with a new workflow if you're switching back and forth from Bitbucket to GitHub.
I looked at Bitbucket a long time ago, and it wasn't nearly as similar to GitHub as it is now, and that makes a lot of sense. It's got Pull Requests, and it's got a very nice source view:
Many will say It's just like GitHub's - which is a good thing. Face it - you copy what's a great design and works well. This is one of those cases.
The thing I like about Bitbucket is the free repos for small teams - up to 5 people. In short, they have a different approach than GitHub - repos are free, people are charged. It's a nice approach because it means that non-Open Source projects that you work on with a friend can be private without a cost. GitHub charges for the first private repo, and I don't begrudge them that - I'm a paying GitHub user. But I like the different approach because it gives small groups a leg up.
I'm not going to stop using GitHub, but it's nice to see that Bitbucket exists and seems every bit as good as GitHub for the task. It's something I'll remember.