Has anyone messed around with this? I've found several websites with software, just seems the board would be costly. It's not new, just getting more attention lately. It started out as a military thing, I think.

The boards (if properly equiped) can recieve any type of radio signal and can decode with the CPU. You can even process several frequencies/stations at the same time, including OTA Hi-Def.
One of the few boards I have seen starts at $550. It looks very cool and is a great idea, just pricey at the moment.