@Cymric:
Go to the following site for various PCB & Contact claners/degreasers and look under Tech Aids/Chemicals -> Chemicals -> Cleaning -> Degreaser (or Contact):
http://www.mcmelectronics.comBasically, it's a spray-can cleaning compound, that you spray over a dirty motherboard or a PCB, a computer card, etc., and it degreases the dirt/dust buildup by washing it off, especially the sticky stuff, thus making the cleaning process easier than if you were to use a q-tip dipped in isopropyl alcohol and do it like that. :-)
Of course, it doesn't magically remove every single bit of dust, but it does help a lot. After the sprayed PCB dries off, you use a can of compressed-air to blow off the remaining bits of dirt that still may be left over, here and there, which now come off easily, even if they were sticky before you sprayed the board.