A Covert Listening Device: Bug-in-a-Book

David Simpson was contacted by MAKE to create a spying device, so he came up with Bug-In-A-Book, a wireless listening device embedded in a hollowed out book. As Simpson explains at Maker Faire Bay Area 2011, a project using scavenged technology has flowered into a product with a kit that diy folks can build and experience for themselves.

http://www.bug-in-a-book.net/home.html
http://makerfaire.com/pub/e/4954