I've posted a video on youtube that demos my free SdrDx software for OS X (10.5 and up, Intel only) supporting the RFSPACE sdrs.

Here's a link to the video of version 1.10 (beta):

http://www.youtube.com/watch?v=c26pGueYdTM

...you can learn more about SdrDx at fyngyrz.com:

--Ben
AA7AS