Actually, just did some research and there's a case you can buy for 9.90 with free shipping. Looks exactly like the 360 250 gb case and they say it's an easy install. So far no complains from people and it's a legit site.
http://www.dealextreme.com/details.dx/sku.48653
Do external hard drives for computers work because flash drives work?
I also have a 60 gb Xbox 360, but it gets too hot when I play, causing the room to get extremely hot where I start busting a sweat. i was going to get a fan, but don't trust 3rd parties.