Picked up from joat that MetaGeek (makers of the Wi-Spy wireless spectrum analyzer USB device) may be gearing up to release Chanalyzer 3.0 soon. Also, they have a Netstumbler replacement for Windows called Inssider.
As much as my Wi-Spy is a cool little toy, the price is still somewhat high. I got mine back when it was only $99, but now that same device is $199 and the higher quality one with an external antenna if $399. Not sure I can recommend this to anyone but people serious about their wireless spectrum needs. I would suggest it to anyone with a wireless network in their business, however. Cheap price for this sort of tool.