I'm an amateur filmmaker and just came across a problem.
I attached a decent sized tripod to my camera, a Canon XH-A1. When I was done with it, the tripod wouldn't release and eventually the screw got snapped off and left inside of the camera. Now I have a small piece of metal stuck inside and I can't find a way to get it out =(
Any suggestions?

You might be able to get it out with a screw extractor: http://homerepair.about.com/od/interiorhomerepair/ss/screw_extractor.htm

If it got stuck, it was possibly cross threaded going in. there are several ways to remove it, but you might want to use someone with some experience rather than risk further damage.