Computers sure are handy when they are working (TreeHugger would have a tough time making it without them) but once they've chewed their last byte, things can get a little messy. Toxic chemicals, carcinogens and heavy metals are all part of what makes their clocks tick, and improper disposal can bring them all a little too close for human comfort. Computer recycling is nothing new, but getting your old electronics to the great motherboard in the sky can be tricky to do responsibly. For years, developed countries have been exporting tons of electronic waste for inexpensive, labor-intensive recycling and disposal, mostly to China. It's been illegal to import e-waste into China for dirty recycling and dumping since 2000, but smuggling, corruption and China's appetite for scrap keep it coming. An article over at Salon has some good tips to prevent your old electronics from being melted down over a rudimentary stove or being tossed into a landfill.
One of the best ways to get clean recycling is simple: just ask questions. A reputable recycler should be able to tell you where hardware is sent, and if the company exports or uses prison labor. The recycler should also be able to tell you how it handles data destruction; you'll want the recycler or reuse organization to wipe the hard drive for you so any personal information doesn't end up where it doesn't belong. If you are donating your equipment to a reuse organization, ask if equipment is tested before it is passed on for donation and if the company only ships working equipment. Ask who their recipient organizations are. If the answer to any of these questions is, "We don't know," or, "We can't tell you," it may be time to send your equipment elsewhere.
One of the easiest options is to use your computer manufacturer's recycling program, though most major manufacturers charge fees and require you to do the packing and shipping. The Silicon Valley Toxics Coalition, a good guide to responsible recycling, finds many of the manufacture take-back programs wanting and publishes a report card on the environmental effectiveness of most of them.
The Rethink Program, hosted by eBay has a good computer recycling FAQ section and many useful links to recyclers, as do CompuMentor's Tech Soup site and the EPA's eCycling website. Be aware, though, that the recyclers listed on these sites have not been vetted or approved by these organizations in any way. The Basel Action Network also carries a list of electronics recyclers that have signed their stewardship pledge, under which recyclers agree not to export e-waste or add it to landfill, or use prison labor, and to document where equipment, parts and materials go.
If your machine still functions (and not just as a paperweight), then seeing that it is reused is perhaps the best option. Companies like RetroBox and FreeGeek build computers out of salvaged parts; the latter has a list of like-minded organizations that can be a good starting place for recycling or reusing your machine. For a more complete list of NGOs, government agencies and manufacturers who recycle, check out the article at ::Salon.