Todd, VE3LMM, gave the club a terrific talk last night about the RTL-SDR TV tuner dongle available online for $20. The dongle can be easily converted into a wideband (24 to 1766 MHz) SDR using free software.
There are other SDR dongles out there like the Funcube Pro+ (at $200) but the RL-SDR dongle at $20 is the cheapest yet and for $55 you can get a shortwave up converter.
So aside from listening to shortwave and VHF/UHF signals what else will these SDR dongles do?
Depending on the IF out from your big box radio the dongles can be made to work as a panadapter. Now considering some panadapters sell for $600 this is an amazing deal.
The dongle can work as a portable radio scanner using some smartphones and tablets. It can also be used to decode RTTY, PSK-31 and a bunch more digital modes for printing on a computer, tablet or smart phone.
A Raspberry PI can run SDR remotely and then send you data via the ethernet or wifi.
All this for $20.