Okay, so I just went out and bought a power meter thingy today. You know, one of those things that plugs into a wall socket, and lets you plug other things into them. It can display current Watt consumption, as well as measure Watt consumption over time, keeping track of min/max/average...
So, here's a few stats for your amusement.
ASUS A8N SLI Premium
Antec Neo HE550EC PSU
4x512meg Corsair TWIN2X1024A-6400 memory (PC800 DDR2 RAM)
Socket 939 AMD64x2 4400+ (2.2GHz, rated 110W max)
GigaByte GV-NX76T256D-RH (passively cooled GF7600GT/256meg GDDR3)
Western Digital Raptor, 74gig, 10.000rpm SATA drive
LiteOn LH-20A1S-10C, 20x SATA DVD-RW burner
Computer, turned off: ~6W (need to flip PSU switch to get 0W!)
Computer, standby: ~9W
Computer, on & idle: ~153W
Computer, 1 core maxed out: ~187W
Computer, 2 cores maxed out: ~203W
Locate32 indexing, ~3-7% CPU usage: ~160W
Furthermore, my WAG300N-EU combined ADSL2+ modem+router / 4 port 100mbit switch / wireless access point draws ~6.8W, and my 5-port NetGear GS105 gigabit switch draws around 6W.
I'll return later with stats on my TFT monitors