this is nothing short of AWESOME..cheap SDR?

[rwfisher]

Apparently you can hack some USB TV dongles to act as a SDR:

http://sdr.osmocom.org/trac/wiki/rtl-sdr

There are even OSX ports for the software lurking around

[zackers]

I just got a Softrock Ensemble II SDR going. Very easy kit to build if you're experienced at surface-mount construction. This is my first venture into SDR and I'm impressed so far. I'm using the HDSDR software at the moment. I also got a Creative X-Fi Soundblaster USB card (SB1095). It's an improvement over my computer's built-in soundcard.

[Pigmeat]

This DIY site www.instructables.com has several projects on hacking dongles to make SDR's.

There's a lot of other interesting DIY radio stuff there. I'm still searching for the legendary Fansomitter among the files.