Wired News reports on the electromagnetic exposure debate: I've been reading research into this issue since the early 90s, including the legendary VDT News, Microwave News, and the actual text of the Swedish and Finnish studies so widely cited. The fact is that 25 years after widespread adoption of VDTs and CRTs in workplaces, there is no pattern that has emerged of any kind.
Prudence dictates caution, however, and, fortunately, that caution has been taken. Devices are constantly being redesigned to emit less and less electromagnetic radiation. LCD displays, for instance, emit a fraction of what CRTs do. New cell phones less than old cell phones. And so on.
In my dealings with people, the main confusion is the difference between radio waves used to carry information and ionizing radiation which can actually disrupt living tissue and cause a variety of reaction and disease. (As someone who voluntarily subjected themselves to 4,000 rem for part of a successful cancer treatment four years ago, I believe I can speak to the difference.)
Radio waves at the wattages we're used to dealing with don't knock apart your DNA, cause burns, or otherwise cause harm. Microwaves, in which category the 2.4 GHz spectrum and 5 GHz spectrum used in 802.11b and 802.11a respectively fall, require high intensities at close distances to produce a measurable reaction of any kind.
As the Wired News article reports, the governments standard is one inch per watt distance out of sheer caution, not empirical evidence; Wi-Fi devices tend to operate below 100 milliwatts, meaning you shouldn't be closer than 1/10th of an inch to the actual broadcast source.
Electromagnetic radiation dissipates from its source in an inverse relationship: the power drop-off is drastic even a few inches away, much less feet.
The next time someone warns you about the cell phone or Wi-Fi card or microwave oven say, honey, there's no enough energy by the time it hits me to change the temperature of water a millionth of a degree.
I hope that a long-term study (of which many must be underway) will finally reveal the actual risk or lack thereof. I do believe there is some correlation between electromagnetic radiation and the potential for physical reaction. The evidence to date, the most convincing and reliable out there, doesn't create any worthwhile extrapolable link.