[E. Pluribus Unum]

I actually bought one a few weeks ago. Haven’t used it yet.

http://www.amazon.com/gp/product/B008XFDHWW/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1

[RckyRaCoCo]

Lot's of good RTL/SDR info here . The Hak5 crew have other YouTube videos for aircraft tracking(what I use it for), and other uses as well. Cheap geek toy.