You seriously dont know? Your making me laugh man.
.....
Standing the 360 up, is not its prop prosition. Its NOT meant to be stood up. IF you stand it up, you will get scratch rings around all or most of your games. I know that for a fact, as Micrsoft has told me, the owner of a game store who repairs 360 games has told me, and I've seen my freinds 360 do it when he stood it up.
Heck, I think I even read not to stand it up in the manual. :S
So yea, dont stand it up or you're disks will stratch. May take a while to become noticable, but I Promise you. It will happen. If you dont belive me, try it or phone Microsoft.