Not too long ago -- about one decade -- it was easy to get rid of a CRT monitor. Just like an old TV, you could schlep it on down to the dump, throw it in and forget about it. In high school, I worked as a student worker in the IT department at the local college, and I remember feeling quite environmentally conscious because we compacted old CRTs in a hydraulic press before throwing them into a dumpster. But with up to five pounds of lead per display, it wasn't long before state governments wisely started banning the practice.

To fill the waste disposal void, a number of computer recycling firms sprang up—and not just out of a concern for the planet, either. From processors to motherboards to monitors, computers contain fairly large and fairly easily accessible amounts of precious materials such as gold, platinum, and silver, along with other useful metals like aluminum and copper. Once extracted, these materials are resold to computer manufacturers and other electronics companies, reducing the need for some additional materials to be mined and processed, and netting a tidy profit for recyclers.

However, as a recent 60 Minutes expose pointed out, not all computer recyclers are created equal. Along with all that valuable material, modern PCs also contain a rogue's gallery of toxic, carcinogenic, volatile or otherwise dangerous chemicals. As National Resource Defense Council scientist Allen Hershkowitz explained to 60 Minutes' Scott Pelley, the list includes "Lead, cadmium, mercury, chromium, polyvinyl chlorides. All of these materials have known toxicological effects that range from brain damage to kidney disease to mutations [and] cancers."

With all these toxic chemicals, many American-based recyclers find it cheaper to simply export wholesale to China, allowing the recycling to take place in disturbing conditions, with some parts reprocessed by prison labor [pdf], and the toxics simply dumped in nearby landfills. Fortunately, concern over the conditions has led a number of American organizations to plot out with abundant clarity how they recycle machines, and news sites from Salon to Treehugger gather links and basic information on how to make sure your old machine is disposed of sustainably.

But with some 130,000 computers thrown out each day in America alone, I think the best course of action is to keep your old machine running as long as possible, especially if it's an energy-efficient laptop. While the latest version of Windows or OS X might not run on your machine, many software companies and third-party sites like versiontracker have older copies of software that will sap up fewer resources on an old computer.

Hardware upgrades like more RAM or a larger hard drive are generally cheaper for older models, giving you a performance bump for far less cash than a new machine. And for the truly geeky, Linux, the quirky, free operating system, has been re-written to work on machines well in excess of a decade old. And don't forget about donating your old PC as a way to really feel good about filling a need.

So don't let style drive you into a new computer purchase; the longer you keep your old machine running, the better it is for the planet.

Image: 60 Minutes