There are more cool things to do with a computer. Open the harddisk, power it up and let it spin fast. Put a pencil through a CD and put the CD vertically on the platter edge. Release when the CD is spinning REAL fast. It climbs up the wall to the ceiling.
Then theres the raiders-of-the-lost-ark meltdown. Put the motherboard sideways and hold a blowtorch or better heat gun against it. Watch the parts just fall and leave you with a clean board to use as decoration somewhere. Watch out for the capacitor flames! They can really explode, especially IBM ones.
Another nice trick is to be able to submerge the running computer in a liquid so it doesnt shut down. Some oils work well. If its successful you can disconnect all fans and let convection give you a silent PC. Overclocking sites will help with this but its more cool with brand new hardware.
Burning a PC isnt too bad. Flames have different colors on the ribbon and various capacitors, and of course the exploding IBM capacitors.
The harddrive magnets are awesome. Give them to a friend and tell him to put them together. They attract SO hard the user is pinched bad. Then ask em to try and pull em apart
. Put it in your pant pocket and walk around the library computers if they have CRT monitors.
Hmm now that I think about that, I wonder what will happen if you give a girl a really strong spherical magnet to put in her vagina and walk around an industrial area. She oughtta love it.
Speaking of harddrives, just dangle one from its power cord and swing it around. The gyroscopic effect is cool. This is more cool with the 15K RPM Atlas drives. Or open it and make a significant bump/hole on the top platter. Now make it spin fast and hold a small pencil at an angle against the platter. When the bump/hole hits the pencil it'll launch it high.
Harddrives are so cool, open one up and use a small program to access the sectors manually. You can more the arm so precisely.
If youre not that much into electronics just drive your dads SUV over the casing. Or bump your bike into it a few times. Theres a weird pleasure to be had with that. Anyone else tried to chainsaw a running harddisk?
There! How can you compare all THAT with merely giving it away to someone who'll be frustrated with its speed and buy a new one anyway.
note: I'm kidding about all that. Old computers with Linux etc are very useful and educational.