In the process of trying (simply as a volunteer) to help some newly arrived international students get their WiFi-equipped computers to access the campus network, I have discovered that the area has a ridiculous number of wireless networks, many of them on the same channel. Some have been established by this particular academic institution (one for the library, one for the student lounge, one for a popular campus gathering place, two for the housing complex, and perhaps others that I have not yet identified).
Then there are networks established by the institution next door, plus other that are not identifiable by their SSID (e.g., simply "Router!") but perhaps are home systems belonging to nearby residents. And who knows how many more nearby networks are not broadcasting their SSIDs?
According to the Netgear Web site, only Channels 1, 6 and 11 have no overlap. Other combinations may have overlaps and interfere with each other, resulting in low throughput if the systems work at all.
So what will happen when wireless networking becomes even more popular? Will access become even more difficult?
This is quite apart from the susceptibility of WiFi connections to interference from cordless phones: our own home WiFi connection dies whenever the 2.4GHz cordless phone is in use. And is anyone keeping in mind that Channels 1 through 6 overlap with a band allocated for use by the Amateur Radio Service, where operators may use vastly more power than wireless networking systems and may blot out WiFi communications over a wide area? Be thankful that this is not yet a highly popular Amateur Radio band and that highly directional antennas are normally used on that band.