Ok, so I just finished my first stir plate build. I loosely followed the Anthony_Lopez "Cheap and Easy" version. It turned out pretty cool. I swapped out the project box for a cigar box ($2 at the local cigar shop) and nylon bolts/nuts for the regular metal ones. Also, since I didn't have a hard drive laying around, I swapped the HD magnet for 4, 1/2" 10 rated magnets from Hobby Lobby set up ++-- on the washer glued to the fan.
Originally, I thought the nylon nuts/bolts would be best, since it wouldn't interfere with the magnets on the fan or the stir stick, but I was surprised when I got it all hooked up! The clear computer fan I bought from Fry's ($3.90) lit up and glowed through the bolts. Pretty cool...
Anyway, check out pics and let me know what you think.