Hehe, Thumper is cool, same concept. Well here was how I did it. You take your Keyboard apart, and look for this chip:
Then you start shorting out the Spider legs comming off it. Start by going Pin 1 to pin 2, pin 1 to pin 3, pin 1 to pin 4... then pin2 to pin 3, pin 2 to pin 4...... On and on till you find which combination gives you the keypress "1". You have to have your keyboard plugged in and computer powered on and in a txt editor so you can see what you are doing to the computer. The Red Line represents how you short them, I just use a 6 inch wire bared at both ends.
OK, so you have found the "Right" combination, you solder 2 wires to the chip as illustrated with the Blue Lines and take those to a Headphone jack available at
http://www.radioshack.com/product.asp?c ... id=274-248
Then Drill a hole in side of keyboard and mount it.
Then you make the Timer, there are a couple Resistors that control the discharge rate of 2 capacitors, that controls the Timer. So by using different sizes of Capacitors / Resistors, you get different delay times, Mine clicks about every 1.5 Seconds. Then you take the Output of the 555 Timer, also available at raidio shack
http://www.radioshack.com/product.asp?c ... d=276-1723 and connect them to some Reed Relays. If you value your sanity, don't use standard relays, I leave this running non stop, and the constant clicking if I could hear it would drive me nutz. Reed Relays are quiter. Then take the 2 ends of the Relay, wire the headphone plug to that, I usually just chop the end off an old set of headphones, and wallah, you can Forage all day with no software. PS, I also did this to my mouse which has helped me out a couple times when working on computers and I find I have 17000 viruses and it wants me to click next on each one individually :)
Well, that was it :) Takes about 45 minutes to assemble (personal time may vary) costs about $15 but you will probalbly have leftover parts. and was much easier and cheaper than hitting all the Thrift stores for geared products like I did for my first one buying all kinds of RC Cars and paper shreders :)