I'd decided that since the tivo had the hard disk, it needed better cooling, and it went outside.

I originally put my DTiVo under my TV, where it could be muffled by the glass doors of my equipment cabinet. It didn't work. The TiVo was overheating on a regular basis and shutting itself down; the internal thermometer claimed it was getting over 50C, yet calling that "normal" temerature!

Now, I have the DTiVo on its side, outside the TV, exposing the entire bottom of the unit to the air. It's now running 10 degrees cooler and has never had subsequent heat-related problems. The noise issue is only really noticable if I'm listening to music with quiet parts. Watching normal TV, it's not really noticable. I've occasionally unplugged the TiVo to lower the noise floor, but it's typically not worth the bother.

Meanwhile, I'm still waiting for the all-in-one HD-DirecTiVo. That will be when I make the big jump.