You want a cheaper cell phone plan, but you feel trapped.

You know you'll get hit with a big fee if you break your contract.

Maybe you shouldn't worry about being in the penalty box, especially when switching carriers can save you hundreds of dollars a year.

Anytime Wal-Mart starts to sell something, you know it's gone mainstream. And last week, the giant retailer started selling unlimited prepaid wireless plans. With its straight talk plan, you get a thousand minutes, a thousand text messages in a 30-day period withno contract and no termination fee.

Prepaid cell phones have come a long way the last few years. They're now a practical, money-saving alternative to contract cell phone plans.

Competition is driving down the price.

"You can save half of what you might be paying elsewhere," said Linda Sherry of Consumer Action.

Here are a few examples.

Boost mobile: Unlimited talk, text, Web, walkie talkie, voice mail and call waiting for just $50 a month. You can get a basic phone for $50.

Tracfone: You can get a phone for as little as $15, then pick your plan. For just $9.99, you get 50 minutes a month. For $29.99, you get 150 minutes a month.

Virgin Mobile: Unlimited calling for $49.99 a month. The company has one phone that's free.

And how's the service? In most cases, it's top-notch, provided by one of the big wireless companies.

Add it all up, says Sherry, and you may want to consider the prepaid option.

"In some cases, it will be worth your while to eat that fee because in the long run, you'd save so much money so quickly that it would be worth the switch," she said.

The great thing about a pre-paid plan -- there's no contract. You can stop it anytime you want with no penalty.

"You can budget. You can know and if, God forbid, something happens in your life like you lose your job or something, you're not required to go on paying that. You can just terminate that agreement right then and there," said Sherry.

Prepaid plans let you choose from a wide variety of phones, including smart phones with full keyboards, digital cameras and wireless Web.

The fancy phones can cost $100 or more, but you can usually find a basic model for between $15 and $20.

For more information:

Consumer Reports: Best Cell Phone Service

How to Buy a Pre-paid Phone

Pre-paid Cell Phones May Be Your Best Bet