fuchikoma

Basically the 360 is really noisy across all wi-fi channels, all the time, even when it's off. It doesn't interfere with my network, but I first heard of this effect when it was taking out wi-fi in a dorm somewhere and it was analyzed by the campus staff.

Will that software work with my wifi adapter, or do I have to buy their dongle?

You might be able to get vague outlines of access points on different channels/their power levels with just a wifi adapter, but the actual spectrum graph is measured with their dongle. I also use version 3.3 of their "Chanalyzer" software because 3.4 doesn't work with Windows 7 and version 4 took some features I used out and moved them to a "pro" version that costs more money.