This is a picture of the Arduino completely submerged under Eco-Earth FluidXP Non-Conductive coolant:
This is a shot of me holding up the Arduino just slightly out of the coolant, which I chilled by putting in the freezer for about 20 minutes, and also keeping it chilled while transporting it with a cold compress:
The overclocking part wasn't so bad, but the problem with overclocking the Arduino is that once you swap out the crystals or tamper with the oscillator circuit in general, you can't really program the Arduino with code any more. So I downloaded the simplest sketch I could think of, the Blink sketch. That's the one that blinks on and off every half second.
The normal Arduino is a 16 MHz chip. Mine runs at a little over 32 MHz, and is a Duemilanove. Here's a little video of the "behind the scenes" of how I soldered the new crystal in:
I was pretty nervous putting the Arduino into the liquid coolant for the first time, so I loaded it up with the TempSensor, and had it kick back readings to the computer as long as it could. You can't really tell from the video, but the liquid is freezing cold. The tips of my fingers were a bit numb after a few videos :-)
Anyway, these are probably my favorite pictures of the project - I uploaded some more pictures over at flickr: