Not to mention physics have proven Water is the best compound for heat removal. True you can add stuff like waterwetter or purple ice but it sill takes mostly water. Now if you really want cooling stick in a fridge or build a Freon based system.
The reason isopropyl alcohol stays cool is that is takes heat to evaporate, thus heat is whisked away when the isopropyl alcohol moleclues break free of the confineing, liquid state into the free gaseous state.... be free!!!!
Seriously, it is just another form of evaporative cooling, just like sweating. Unfortunatly, in an enviornment such as what we use to cool computers, the heat capacity of the i-Pr is poor and you would have a significant evaporation problem, which would necessitate a closed and pressurized system (think car radiator). i-Pr is not worth the trouble - just stick to good old H2O, some waterwetter and a little anitfreeze.