Pros: - Usually does the job: blocks cell phones. Works very well in closed areas such as train cars, theaters, cinemas, malls.
- When it's activated it takes few seconds to disconnect someone.
- Battery life time is more than enough, if you use it smartly: activate it only when it's needed (when you want to block).
- Both useful (quiet down annoying people) and funny for abusing the cell phone addicted users.
- Relatively cheap, considering alternative products.

Cons: - Blocking range is limited, usually up to 3-5 meters.
- Doesn't work well or at all in places where the real antenna signal is strong, such as in the street, or in office buildings in rooms near windows.
- If the charger is connected only to the device (and not plugged to the wall), it drains battery slowly.
- The black plastic antennas are not connected too strongly. If you carry this device in the pocket or in a small bag they bend and you need to straighten them.

Other Thoughts: I have two such devices, and both work similarly, with same pros and cons I wrote.
I'm not sure how safe this is for health, compared to regular cell phone or cellular antennas.
People who understand physics and engineering that I asked seem to suggest it's safe though.

Bottomline: Overall I'm satisfied with this product, but it could be better.

Pros: My room is located in the far corner of the office and people thought that that's the best place for their phone calls. It's annoys me. But this thing gives the rest of my ears and allows me to concentrate on work.

Cons: Build quality is a bit poor. One of the antenna caps was broken, another one going to do the same soon.
AC adapter is not compatible with my "Euro" outlets.

Other Thoughts: Cell phones are not always loosing signal in a second. But anyway sound makes crappy and you definetly can't continue the conversation.

Bottomline: It works! If phone calls annoying you - buy it.

Pros: It works to block cell phone signals for any carrier in US. It works with verizon, att, sprint, and old iden networks like nextel. It can be charged by car charger or wall charger and internal battery holds good charge. I tired it and it blocked signal on all cell phones in classroom for about 3 hours. it has charging light and turns off when battery is full. Also it can be turned on while chargng. It has green light when in operation.

Cons: can be made smaller to fit in front pocket. it can get warm after continous operation but not bad.

Other Thoughts:

Bottomline: This is worth the money. It is very helpful when need to shield a personal area.

Pros: Before I got this, everyone in my classroom would text eachother and cheat; Not only that, but just answer calls, and text friends, etc etc. Within 10 seconds of the ON button, all calls and texts ceased!!
FOR DAYS They were all panicking and trying to poke their phones out of the window to get service... They gave up, and stopped checking.. Now I can learn in peace! Great quality, charging circuit cuts when fully charged! EXCELLENT!

Cons: Does not cut Telus here In Canada. Only 2 students in my classs use telus, and they rarely bug me; PLUS, when 2 people have service, and the others dont, they do not suspect a jammer, they just suspect their phones and network!!!

Other Thoughts: This product was obviously improved over previous versions. The casing is solid, the charger stops charging when the jammer is fully charged. I got this item within 3 weeks of ordering which is VERY FAST for Canada. This exact one sells for a few hundred dollars on some sites, so for the price available here,and the excellent service, it is truly a deal you have to take advantage of!!

Bottomline: If you want peace and quiet, and to get rid of those nasty cheaters, and yakkers who have no respect for your privacy, BUY ONE.. Turn it on, and LAUGH . The hardest part of owning this is holding in your laughter.
BUY ONE!