ebay www.ebay.com Freecycle www.freecycle.org Sign up and post any items that you can give away and not throw away. You would be surprised what some people want!
Craigslist www.craigslist.org This is a great place to sell or buy used items and equipment. Craigslist has local sites so you can narrow your market to greater Boston.
Gazelle http://www.gazelle.com/ This is the site for selling or recycling your electronic gadgets.