6 pesky fees that are eminently swat-able

— -- Doesn't it feel like every time you make a transaction — rent a car, use a credit card, invest in a mutual fund — some fee you didn't expect and don't understand claims more of your money? It's hard not to feel cheated. What are those fees for, anyway? Are they justified? And most important, is there a way to avoid them?

Staffers at USA TODAY recently chose a few notable stinkers: six of the most truly irritating consumer fees. Happily, in many cases, these fees are as avoidable as they are nasty. Behold a few members of the hall of shame — and how you can stop them from burning you.

Car-rental fees

What they are:Failing to do research before you get to the car-rental counter could trigger insurance and other fees that exceed the cost of renting the car itself. Yet chances are, if you already have an auto insurance policy and are charging your rental on a credit card, you won't need to buy any extras at the rental counter.

How to avoid them:Call your credit card issuer and review your auto, homeowners' and health insurance policies before hitting the road. A majority of credit card issuers provide collision protection — which covers you if the car is damaged or stolen — if you charge the rental to your card. But this protection often pays out only after your auto insurance kicks in.

Meanwhile, supplemental liability coverage, which insures you against damages if you cause injuries or death to another person, is often included in umbrella home and auto policies.

You may also be able to save money on taxes and fees if you rent a car outside of airport locations. Finally, shop around, because rental costs vary widely from company to company.

Bank overdraft fees

What they are:Banks charge you these fees for spending more than you have in your account. At an average of $34 for each overdraft, banks are reaping a record amount — $17.5 billion — each year from these fees.

And banks are making it easier for you to overdraw your account. A few years ago, if you tried to use your debit card to make a purchase and lacked enough money in your account, they'd deny the transaction. Today, most banks approve the transaction — without warning you you're about to overdraw — and then hit you with this fee. These charges can add up if you use your debit card for small transactions like coffee and magazines.