I am getting a receiver with only 2 hdmi inputs. So i will only be able to hook up my comcast HD/DVR and my PS3 via HDMI to the receiver. Would it be possible to just keep my xbox 360 (3rd HDMI) hooked up straight to my tv. And use the optical audio adapter so i can still get the surround sound with out having to use component and sacraficing the HDMI?

So basically can i run the HDMI from my xbox to the tv, and run something from the optical audio adapter from the xbox to the receiver?

That will probably work fine, but you might want to check to make sure that the 360 doesn't do something screwy like disabling the optical out when HDMI is active. Come to think of it, I think I've used the same setup you describe before without problem. I think you're in good shape.

I've got hdmi running from the 360 to my tv, and I'm trying to run an optical cable to the receiver...but I'm not getting any feedback. It seems like this should work, do I need a specific optical cable, or are they for the most part generic? Maybe I'm using one specific to dvd players or cd players?

Optical is optical. One that works for a 360 will work for every TOSLink/optical device.

It's probably a setting on the xBox itself.