Has anyone managed to maintain a friendship with an ex?

I'm curious - are any of you still friends with your exes?
Have you ever gotten back together with an ex?
How did it go/not go


Personally, I keep in touch with one ex and only because we dated for a month and it was never serious. There were never feelings and I love you's involved so it didn't feel like a real relationship to me. Was easier to be friends. The others I avoid like the plague, have never been able to get back with someone after breaking up with them