Kramden would be my suggestion if you are in North Carolina, USA:
http://kramden.org/donate-a-computer/
Depending on how one is to interpret the "donate" verb; whether it should be to a charity that will use them, a charity that can sell them or just to not put them in the landfill.
In some ways, giving(?) them to an e-cycler that puts them on eBay is addressing that last problem, it just robs you of the tax write-off.