Update: I put a much better spectrum analysis video here. Enjoy!
In the first bit of video, you can see my 802.11b network beacon banging away on channel 11. Later, I turn on the Bluetooth discovery on my iDevice – massive spectral shrapnel!
It's written in Python using the PySide Qt bindings. USB support is provided by PyUSB 1.0 on top of libusb 1.0.
If you don't have an Ubertooth One, you know where to order one, right?
Next on the agenda: add a legend to the display, improve scan speed (by somehow reducing USB and PLL/VCO tuning time), and bundle up Mac and Windows builds so people can download and play with them on non-Linux platforms without having to get a whole toolchain set up.