I put mine in horizontal position...I've read an article on the Net from Ben Heck, the guy who made the portable xbox360 and whole lot of other modified consoles, and in the article he said THEORETICALLY if we put the 360 in horizontal position the 360 should be a bit cooler compared to vertical position..

nway as in previous post it all depends on luck...my previous 2 3ROD 360s i put in vertical position...now i put my Elite in horizontal position...i noticed that it's a bit cooler even after playing for 6 hours...touchwood that i wont kena 3 ROD again...