Yeah, I'm folding 24/7 with the PS3 (taking time out for movies and some Motorstorm). I have my X2-4800+ also folding, but throttled on 50% of one core. I thought about folding on my HTPC and my Domain Controller, but decided it would be too much of a PITA on the HTPC, and the DC, no matter how much I throttled the CPU, pretty much choked (was just a test anyway...I figure it only does my domain authentication, routing to the internet, runs DNS and DHCP, and serves my files...didn't need another app running).
I have plenty of computers in the house I *could* be folding on, but I don't want to up the electric bill. I figure the main computers folding (and infrastructure) are on 24/7, so may as well do something useful.