I got a black mesh case for my sn45g and put a fan blowing out just next to the graphics card! Quite neat and has lowered temps significantly. Runs cpu 42 idle and 47 after good game of ut2004. Case 37 idle and 41 post ut. Much better!
***Update***
Just upper to 2100mhz and had to increase voltage to 1.7 on processor but idle temp for processor only up to 44. Unfortunately not the best of o/c 2500+ but not bad.