Actually, this is a well known issue and not an infringement with the FCC. WiFi, namely the popular 802.11b and 802.11g, uses a slice of the frequency spectrum in the vicinity of 2GHz (specifically a 2.4GHz band) that is not regulated. Instead, this particular range of the spectrum is designated for amateur/experimental operator use and for certain types of short-range commercial devices.
Behold! This is the same frequency range used by the latest and greatest 2.4GHz cordless phones. My guess is that you're using a 2.4GHz phone in close proximity to your WiFi device(s). One possible solution, as already mentioned, is to cycle through the different channels to try to find a combination that minimizes the interference. This may not always work. Another approach is to rearrange the layout of your devices to keep potentially interfering devices away from eachother. The final resort, change one or more of the aggressor devices.
FYI, phones aren't the only devices that cause interference in this range. Certain kinds of microwave ovens and even TVs can interfere with your WiFi reception. If you want to read more, just do a web search for 802.11, WiFI, interference, or any combination of the above. It's common enough that you should be able to find plenty of links discussing sources of interference and ways to minimize them.