In the process of cleaning out closets etc we've found an amazing number of old cell phones. It's really amazing considering I never even had a cell phone 10 years ago. Now I have at least that many old ones!
I've known that we could donate old cell phones for the troops to use or for use by organizations that combat domestic violence. If you have an unused cell phone and are in an area where you're not sure where to donate it I found this organization that makes it very easy. Log on to WirelessFoundation.org and click on "Call to Protect" tab to get a prepaid mailing label or find a local drop off location. They will refurbish and resell your unneeded cell phone, donating 100% of the proceeds to organizations that combat domestic violence.
If you have fairly new cell phone, I also found a place that will buy your used cell and as an added bonus they plant a tree for each cell phone they buy. Go to GreenPhone.com and answer a few questions about your phone, it's quality and list any accessories you have. They will give you a price quote and you can print a prepaid shipping label. Box the phone and any accessories up and drop it by the post office. Then watch for your payment to arrive by check, PayPal or Obopay. Easy as that.
I know you can always put your phone on ebay but for those who want an easy way to get rid of some excess electronics and don't want to hassle much I thought these were some good options. We're currently waiting on our $50 for my old PalmPre.