Renegade Antennas: http://www.metageek.net/node/1601
Please see the attached recording.
Consider the obvious interference spikes, especially on channels 1, 5,
and 9.
Cordless Phone Brings Down the WLAN

Microwave
Cordless Phone Interference: there are Plantronic Headsets, WLAN, Wireless Mice, and a cordless phone in this recording. Check out the notes
802.11g Dropbox aynchronization: I was synching up a new computer to my dropbox account, you can see the access point further away (lower dBm) and my network card (higher dBm) communicate with the access point. It looks pretty cool!