I guess it depends on where you live. I'd search for some sort of giveaway communities on Facebook or elsewhere online. It will probably be something local, due to shipping costs etc. For example in Croatia I give old hardware away over:

- poklanjanje.com ( https://www.facebook.com/Poklanjanje-142113603722 )

- cipele46 ( https://www.facebook.com/Cipele46 , http://cipele46.org/ )