Cell Phones Jammers: Tempting but Illegal

And available in a variety of styles and prices.

The Jammer Store!

Link to May 4 Milwaukee Journal-Sentinel article, "Oak Creek library might buy gear that blocks cell phones".

Numerous comments give this idea a big thumbs up, but the FCC provides the buzzkill.

According to howstuffworks, an alternative to cell-phone jamming involves using things like wallpaper or building materials embedded with metal fragments to prevent cell-phone signals from reaching inside or outside the room. Some buildings have designs that block radio signals by accident due to thick concrete walls or a steel skeleton.  One of those buildings is Helen C. White Hall on the UW-Madison campus, at least the windowless room that serves as my occasional office.

Related articles:
Principal Installs Cellphone Jammer But Forgets To Check If It's Legal. (In Canada. Techdirt, 4/2/2009)
Devices Enforce Silence of Cellphones, Illegally. (New York Times, 11/4/2007)
"Hope You Like Jamming, Too: Cell-phone jammers may soon be all over". (Slate, 12/5/2003)