In response to the question about Muse and Radiohead (as a very big fan of both): I find that there is VERY LITTLE similarity. The only similarity that they hold is Matt and Thom using falsetto. To me Showbiz doesn't really have any Radiohead-influence to it, it feels more Post-Radiohead (like Coldplay's "Parachutes").
If anything Muse has EXTREMELY STRONG similarities to Rage Against The Machine which is no surprise since they're heavily influenced by them. In fact if you listen to a heavy Muse song and a RATM song you'll notice Matt and Tom's guitar tone is almost exactly the same. Not to mention Matt's singing at times can be frantic and angry like Zack's, also RATM does have a pretty good drum and bass backing, same can be said if not more about Dom and Chris.