People have always been proficient at making trash. Future archaeologists will note that at the tail end of the 20th century, a new, noxious kind of clutter exploded across the landscape: the digital detritus that has come to be called e-waste.

More than 40 years ago, Gordon Moore, co-founder of the computer-chip maker Intel, observed that computer processing power roughly doubles every two years. An unstated corollary to "Moore's law" is that at any given time, all the machines considered state-of-the-art are simultaneously on the verge of obsolescence. At this very moment, heavily caffeinated software engineers are designing programs that will overtax and befuddle your new turbo-powered PC when you try running them a few years from now. The memory and graphics requirements of Microsoft's recent Vista operating system, for instance, spell doom for aging machines that were still able to squeak by a year ago. According to the U.S. Environmental Protection Agency, an estimated 30 to 40 million PCs will be ready for "end-of-life management" in each of the next few years.

Computers are hardly the only electronic hardware hounded by obsolescence. A switchover to digital high-definition television broadcasts is scheduled to be complete by 2009, rendering inoperable TVs that function perfectly today but receive only an analog signal. As viewers prepare for the switch, about 25 million TVs are taken out of service yearly. In the fashion-conscious mobile market, 98 million U.S. cell phones took their last call in 2005. All told, the EPA estimates that in the U.S. that year, between 1.5 and 1.9 million tons of computers, TVs, VCRs, monitors, cell phones, and other equipment were discarded. If all sources of electronic waste are tallied, it could total 50 million tons a year worldwide, according to the UN Environment Programme.

So what happens to all this junk?

In the United States, it is estimated that more than 70 percent of discarded computers and monitors, and well over 80 percent of TVs, eventually end up in landfills, despite a growing number of state laws that prohibit dumping of e-waste, which may leak lead, mercury, arsenic, cadmium, beryllium, and other toxics into the ground. Meanwhile, a staggering volume of unused electronic gear sits in storage—about 180 million TVs, desktop PCs, and other components as of 2005, according to the EPA. Even if this obsolete equipment remains in attics and basements indefinitely, never reaching a landfill, this solution has its own, indirect impact on the environment. In addition to toxics, e-waste contains goodly amounts of silver, gold, and other valuable metals that are highly efficient conductors of electricity. In theory, recycling gold from old computer motherboards is far more efficient and less environmentally destructive than ripping it from the earth, often by surface-mining that imperils pristine rain forests.