The Yapper Zapper is one of those devices which fall in to the category of use at your own risk, but it would provide you with a little peace and quiet from the continual annoyance of mobile phones and text messages arriving if that’s what you require.
So if you feel like helping a few people out in the cinema the next time you go to see a movie, simply slip into your pocket and not one mobile phone will ring during the duration of the film. Bliss!
The Yapper Zapper has been designed to block GSM, CDMA, DCS, PHS and 3G signals within a radius of up to 10 m or around 30 feet, and can perform the task for up to 2 hours on a single charge.
Unfortunately devices like the Yapper Zapper are illegal in most countries but if you need one they are available to buy for $109. But use it at your own risk.
Source: Red Ferret