We are talking about different types of radiation here (re: Giorgio's post). Ionising radiation (x-rays, CRTs etc) are more harmful as it is established that they cause cell damage and mutation which may lead to cancers. Wireless access points, handphones and microwave ovens emits electromagnetic radiation (RF - radio frequency) which are non-ionising radiation. Microwave ovens emits high power - 600W to > 1KW for it to work. For comparison, microwave transmitters used for long distant communication emits between 5 to 50W. The emmission from household and consumer portable devices is much,much less so should be 'safe'.
However the jury is still out on the health impact due to long term exposure to low level RF radiation. The FCC guidelines which stipulates limits to the RF emission power is to prevent interference between devices and is not health related. Personally, I prefer to to be safe than sorry. I use handsfree headset as much as possible and switch off wireless routers when not needed (save a few cents also).