Originally Posted by NickW
DECT phones operate in the 1900MHz band and will not interfere with WiFi. I seem to remember being warned that there are some '5GHz' phones that only use 5GHz for base-station transmit; handset transmit is in the 2.4GHz band. Perhaps nmenaker has one of those?
The DECT and Microwave are what I've been told. But I know for a fact that Bluetooth operates in the 2.4GHz range and frequency hops at 600 times per second which can really screw up 802.11B and G. The new Bluetooth standard is supposed to discover, then skip WiFi stations, but there are millions of the old Bluetooth devices out there.