Global Cellular Antenna Booster Strip

Pros: Cheap, easy to install
Cons: can not really tell difference.

Here is the excerpt from the company which I purchased the antenna booster:
The internal antenna booster works like a dish on a satellite to capture and emit a stronger signal. By placing the internal antenna behind the fixed antenna of the phone...

Pros: pretty sticker
Cons: doesn't work

The sticker-variety antenna boosters are a complete joke. Save your money. Nobody can offer a resonable explanation of why it should work, either. If it worked then cell phone manufactureres would install them- but they don't because the antenna...

Pros: It's free, so feel free to try it out.
Cons: By all tests, it doesn't work.

Years ago, I purchased one of these for my Motorola Startac. I even convinced myself it helped a little, but it really didn't. Now you get one free with nearly every cell phone accessory you buy on eBay and other places. The fact that they went from $19.95 to absolutely free should be a red flag that they're worthless. Since I got another free one with my latest phone holster, I decided "what the heck" and stuck it in my phone. I tried it around for a few days and again noticed NO improvement.

If you get one for free and want to try it out, there's no harm, but don't expect real results.