I once heard Matt Damon singing My Funny Valentine...thought that was awesome; he can really sing, man!
So, do yoiu guys no any other actors doing the same thing?

Ummm...not with Jazz but with pop. The Australian TV show Neighbours has a pretty big reputation for it's actors starting up a singing career. People like Kylie Minogue, some curly haired guy (Forgotten his name but he had a curly blonde mullet), Delta Goodren...Dani Minogue used to be in Australian television show called Home & Away. Russell Crowe has a band called 30 odd foot of Grunt (Really Bad).

I suppose there are a heap of actors come singers.

Yeah, maybe... like natalie Imbrughlia...but I'm talking about gooooood music, not some of those commercial stuff