What to do with old parts

Like many of you I tend to accumulate old or broken bike parts and struggle to find a use for them. Since they are so expensive to replace but almost impossible to sell I tend to hang on to them. My girlfriend came up with this nifty idea for an old bent disc rotor. $20 for the clock parts from spot light. The rotor cost me $80 to replace so this clock is worth $100 but I think it will make a perfect addition to my shed...when I have one.
I reckon I could find a bunch of old rotors if I ask around. Might even start making these just for the fun of it. See if I can donate them for prizes or something at local bike meets.