Nowadays, you can just about mount anything to anything (if that makes sense!). I have a friend with a Canon EOS 1Ds that uses Nikon lenses. Its just incredible.
http://www.cameraquest.com/adaptnew.htm has plenty of adapters.
Just another note on the wide field set up you maybe thinking of - don't forget that many DSLRs have a magnification (1.6 multipler)
http://www.luminous-landscape.com/tu...dslr-mag.shtml explains this well. If you intend going really wide i.e. fish eye, then you'll need to take this into consideration.