When you’re ready to part with that dear old computer, don’t throw in the trash. Earth911 let’s you search for local recyclers who take not only electronics but also plastics, household goods, automotive parts (think oil and tires), and lawn and garden chemicals.
Its especially important to recycle your electronics. Many computers contain lead which if thrown in the landfill, can seep out. I’m personally not big on drinking lead water.
The other interesting part on this is that you can recyclers for your CFLs (compact fluorescent lamp). These lights go a long way in reducing energy demands but the huge downside: mercury. The bulbs work by exciting a small amount of mercury inside the tube to produce light. Wikipedia can explain it much better.
Finally, if there’s a Staples store nearby, you can take your computer, printer, monitor, whatever you have into them. Staples is the first big retailer to offer electronics recycling in store. The big items do cost money. Its $10 to recycle your monitor, printer, or computer tower. However, that price is fairly competitive with everything else I’ve seen. Small items (keyboards, mice, speakers) are free to recycle.
Update Nov 17, 2007 – CNET UK posted an article on recycling your old electronics.