Love my 20in iMac (2.13GHz processor). Great screen, great software, much better experience than Windows. Only one niggling problem: fan noise. The iMac is incredibly quiet compared to any other desktop computer I've had. But there's still a background whirr. This is par for the course, I guess. I've checked top and nothing is getting above 2-3% of processor. It's not as if it seems there's a hairdrier in the iMac. It's just a low whirr, like I can hear an air conditioning unit next door. Does anybody have any tips for a quieter iMac? Silent would be lovely, like my iBook G4 notebook, although I might be asking too much.