These are all very good ways to donate / recycle an old phone, the main thing is just don't throw it into the landfill.
Another good idea is if the phone still works, most carriers will allow you to use the old phone as a prepaid phone. Why not put some minutes on it and "donate" it to someone you know, that way you know it was put to good use. Check with a local church if you don't know someone in need.
Sounds a good idea! I bet that's the best thing we should do to our old cellphones that we don't need anymore.