I have a Mac mini that stays on 24/7. It acts as my iTunes server, AirVideo server, file server, and few other services. The other day, I noticed that temps of my Mac mini were a bit higher than I had remembered. It had been close to a years since the last time I opened it up to do anything. So I decided to grab my can of compressed air, shut down the mini, and open it up for a bit of cleaning. I was very surprised to find the amount of dust that had found its way in there. There was enough debris in on the CPU heatsink to prevent efficient air flow. I also have a Mac Pro that I hit with compressed air every three or four months. But the Mac Pro also has more fans and holes for dust to get in. I didn't think that the little slits on the underside of the Mac mini would allow so much dust to get in... How often do you guys rip open your Mac minis for cleaning?