At Gibhub, there's great integration between the reporting and code management tools, and the infrastructure supports lots of different styles of open projects. Where I think it really shines is in really lightweight collaboration, where someone can start some work in an area on their own branch, so they don't get under anyone else's feet but, and this is the really useful bit, their work is still visible to interested others on the project. I think this helps people keep a bit more in sync, without imposing *any* management overhead :)
I'm really looking forward to the arduino/android combo, very excited to get things up and working over summer.
Cheers,
James