The reason I mentioned freecycle and recycling centers is because I have seen tons of them in both places, nobody wants them. Recycling centers will not bother selling an imac because there is no money in it, they get stripped as soon as possible and tend to show up by the skid load (same with B&W's actually).

I would feel bad asking for a MDD G4 on freecycle since those still have value, but would have no issues asking for any iMacs. CRT AIO machines tend to take up some space and people get tired of looking at them.