You may be savvy enough to know that you should be careful when using ATMs -- especially if you're doing so at night, at an exposed machine. But our friends at pointed out some other things to be watchful of when using ATMs.

For example, if you use an ATM that belongs to a bank at which you don't have an account, you'll be socked with fees. You'll likely get slapped with a fee from the bank that owns the ATM. And you might also be charged a fee from your own bank for using another bank's ATM. You might think this isn't a big deal, but we're not talking 35 cents here. The average total fee for such a transaction was $2.91 in 2005. If you paid this amount just once a week, you'd be forking over more than $150 per year. What, that still doesn't seem like a big deal? It should. If that $150 were invested and grew at 10% per year, it would become more than $1,600 in 25 years. If you use the other bank's ATM twice a week, you'll likely fork over more than $300 and could lose more than $3,200 in 25 years.

Things get worse, though. Bankrate noted that in 2005, Americans handed over more than $4.3 billion in ATM withdrawal fees when using another bank's ATM. Yikes. Is the trend at least dropping in value over time? Nope. As of October 2006, reported that the average ATM surcharge currently stands at $1.64. That's up $0.04 from the spring of 2006 and up a whopping $0.10 from about a year ago. Since the last survey, 22 banks have increased these fees, while only six have reduced them. And if you're trying to avoid the fees, you may have a rough time -- 98.3% of banks with ATMs assess surcharges.

If this sounds to you as though something fishy is going on, you're not alone. Last year, banking enterprises such as First Data (NYSE:FDC), JPMorgan Chase (NYSE:JPM), and Citibank (NYSE:C) were hit with a class action suit suggesting that the firms worked together to charge inflated ATM fees.

Meanwhile, though, you don't have to be fleeced. You might, for example, simply use only your own bank's ATMs. If it's a small bank, check to see whether it's a member of a wider ATM network. You might also look for another bank, one more suited to your needs. Some banks have such a widespread local presence that using "foreign" ATMs isn't an issue. Other banks will reimburse you for fees charged when you use another bank's ATM.

Drop by our Fool Banking Center for more tips and guidance.

Hot Tip: Did you know that some brokerages offer checking and other banking services? Your brokerage may be better for you than your current bank. Learn more in our Broker Center.

First Data is an Inside Value pick. JPMorgan Chase is an Income Investor selection. is a Rule Breakers recommendation.

This article by Selena Maranjian was originally published on Jan. 3, 2006. It has been updated by Foolish research associate Katrina Chan, who does not own shares of any of the companies mentioned.