5 Quick Ways to Boost Your Cell Phone:
1. A simple piece of wire
Very simple and cheap method using insulated wire.
2. Major boost using empty cans
This one got me from zero bars to three bars, in an area I never get a signal in. I keep this one in the trunk when the weather sucks. The additional wires I got on eBay for a few bucks each. Takes less than five minutes, looks stupid but works well.
3. The paper clip booster
This one didn't work as well as I had hoped, but it did give me an extra bar (which is great when you have zero bars). Good if you're in the office and need to use your cell, maybe for making one of those "personal" calls.
4. The Tesla coil effect
Hands down the easiest one I found. All you need is tape and those little twisty-ties you get with cheap garbage/sandwich bags. Worked better than the paper clip for me.
5. An old radio antenna