Yeah it seems above 800MHz is where a fan is required.

These picoPSUs are pretty cool for a regular ATX connector. 120W isn't bad considering their size. Something like 96% efficient. They still require an external 12V supply of course though which necessitates a further external brick and the bigger bricks (12V 8.5A = 102W) seem to have fans in them. 100W is quite a bit for a small firewall/router/server type combo though.

My MythTV system is currently 3x120GB IDE drives + XP2400 + 2 DVB cards and it's only around 120W. I would like to get that down though, the obvious solution being to have a single drive of course. They do spin down when they're idle.