I recently modified my mini-itx HTPC to make it fanless and completely silent. All it took was a couple of large aluminum heatsinks from HeatSinksUSA, which happen to look quite nice with the silver Habey case, and a Flat CoolPipe from Amec Thermasol.

Here are my specs:
CPU: Intel i3-2100T
Mobo: Asrock H67 mini-itx
Memory: Kingston HyperX 2x2 Gb
SDD: Crucial 64 Gb
CPU Cooler: Custom fanless using aluminum heatsinks and Flat CoolPipes
PSU: picoPSU-160
Case: Habey EMC-800S





More pics and info in this thread.

That's pretty slick! Do those big heatsinks get warm to the touch when your run Prime95?

Also, you're running the i3-2100T---do you think this scheme would be capable of cooling a regular i3-2100 (65W TPD, versus 35W for the T)?

Yes, after 30 minutes of Prime95, the heatsink gets hot. The case itself however is barely warm. So this proves that the coolpipe is doing its job and drawing the heat out.

I think that this setup would handle a 65W cpu easily. The coolpipe can transfer up to 300W, according to the company specs. You just need to be able to dissipate that heat with a suitable heatsink. The large aluminum heatsinks I have work quite well. I would like to anodize them black to improve their heat radiation ability a little, though.