Here is another wacky idea.
What about making an incubator using a plywood box, heat lamps or light bulbs of some sort to generate heat, and then have those connected to dimmer switches to adjust their output. Put the motherboard and system into the box. If my wireless access point can penetrate it then I can skip the monitor, kb, and mouse and just radmin into it to test. Maybe converting an ice chest or styrofoam container would work better than plywood for the wireless. Something like this seems reasonable:
http://www.melodious.com/gate/howto/coop/incubator.htm
I suspect that it would take some fiddling to get right, but I could presumably collect temperatures at a more controlled ambient this way. Just trying to think of ways to get an isothermal environment...
If I can find the stuff to make a decent res for my Little Giant pump I will start setting up a cooling loop tonight. Don't be too surprised if I am testing with the liquidcc surge waterblock for the first few months (it has a hole predrilled for a thermocouple in the baseplate and this same block has been tested extensively by Bill already).