There is a local company in Jax called Unlimited Solutions, Inc. that has some pretty good karma. They take donations of old computer gear and get it to folks that otherwise wouldn't have a shot at it. Their mission statement from their website:
Unlimited Solutions, Inc. is a non-profit 501(c)3 organization dedicated to providing refurbished computer equipment, training, advocacy, and other assistive technology services to individuals with disabilities, their families, and others in the Florida community who would otherwise not have access to empowering technologies. Our goal is to improve the quality of life of individuals with disabilities, by providing them the digital technology and training necessary to open the doors of independence, employment, education, and community.
I've donated some of my old stuff to them in the past. I think that just about the only way I'm ever going to become less of a packrat is by donating stuff. On a lot of levels it bugs me to throw out something that works just because I no longer need it. I'm really glad that these guys exist because Good Will here stopped taking computer donations a while ago. This struck me as strange, but from what the attendant said they were worried about the privacy aspects of accepting computers. The fear being that someone would donate a computer to Good Will that would then be picked up by someone else and they could possibly steal personal info from it and the original owner would hold Good Will responsible. There are, of course, some pretty easy steps to make sure this doesn't happen if you know what you are doing, but I can see where Good Will wouldn't necessarily have the resources to carry this out. I hung onto a ton of old gear for a while because of that till I found these guys. Good stuff.