What Do You Do With Old Computer Parts?

yoyoma writes "I am planning to rebuild our desktop computers. What do other slashdotters do with old computer parts? I would prefer to donate them. These are some old parts that I will end up with: two GA-686LX motherboards with PII 233, greater than 224 MB RAM (the new computers will take DDR), some video cards (Matrox) and possibly two ATX cases with 300 watts powersupplies (looking for quieter, smaller cases). Decent enough, but they will have no hard drives, floppy drives, or CD drives. TecsChange, and this other place accept donation of parts. Has anyone done this? What about the receipts for tax purposes?"