Sigma Pseudo™ Powder Explosive Scent
http://www.elitek9.com/Scent_Detection/SIGMA/sigma-psd-bottles.jpg
Sigma Pseudo™ Corpse Scent Formulation I and II
Sigma Pseudo™ Narcotic Scent Cocaine formulation
Sigma Pseudo™ Narcotic Scent Heroin formulation
http://www.elitek9.com/Scent_Detection/

Dog Off Portable Bark Free, $25.99
http://www.gooddeals.com/images/products/PD01C.jpg
Ostensibly a flashlight...The sound is irritating to dogs...TOUCH THE BUTTON, and it will transmit a burst of ultrasonic sound (not audible to humans) to help train your dogs behavior. HOLD DOWN THE BUTTON and trigger a high-pitched ultrasonic siren (NOT AUDIBLE TO HUMANS) that could repel dogs away.
http://www.gooddeals.com/shopexd.asp_Q_id_E_37

May not be the cheapest UK supplier of these units, but you get the idea.
http://www.spymodex.com/jammer.htm
http://www.spymodex.com/images/pc.jpg
...will work with all cell phones in all countries.It has an effective range of up to 25 metres... Please note that this model has been upgraded from 20Mw to 100 Mw and is not the same as other similar jammers. - US$306.00

http://www.spymodex.com/images/scrambler.jpg
It is powered by a 12 volt mains adaptor or can be used with a battery pack to enable the device portable and is simple to operate. Covering all cell phone systems worldwide, the Monix MGB-1 produces a high powered full 2watts covering a distance up to 80 metres and is a professional cell phone jamming device. -$530

Unfortunately, cell phone jammers are illegal in the US, and so could not prevent this type of disaster.
http://slate.msn.com/id/2092059/
By connecting a cell phone to hidden explosives, and then calling that phone, one can detonate a bomb (the electrical charge that activates the ringer on the cell phone serves as the triggering signal). In May 2002, Palestinian militants in Tel Aviv nearly caused a major explosion when they placed a bomb wired to a cell phone in a fuel truck headed for Israel's largest fuel depot.

A big problem at a White Power demo for antis or police.
Illegal, so do not use. Participants who get on the buses and into the area are thoroughly frisked. Bystanders may not be.

$200. Two hundred.
PHOTO at Murray's CBS site-
http://www.cbsnews.com/stories/2005/03/11/eveningnews/consumer/main679705.shtml
Moments later, a jammer was purchased out of the back room for $2,000.

For a lot less, you can order them online from companies overseas. Menage says more than 2,000 of the jammers he sells every year are shipped to the United States.

"I would say most of our customers are just people who are cheesed-off by people using mobile telephones indiscreetly," says Menage. "Then there is the business sector."

Restaurants, casinos, even churches are buying jammers. But the FCC says, it amounts to stealing, saying cell phone users pay good money to access the airwaves.

"The penalties are huge if you get caught," says Rob Bernstein of Sync Magazine. "Just having a cell phone jammer can cost you $11,000 and a year in prison."

But the thing is, no one has been caught. Most people don't even know they've been jammed.