Starting this week, merchants who accept Visa and MasterCard are allowed to tack a surcharge onto their your charges. Up to 4% of your purchase! Look for an obvious sign posted at the door and near the checkout though...they'll have to post a sign about the extra fee.

How did this happen?? It's the result of a class-action lawsuit by merchants against the credit card companies, which was settled last year.

NBC News reports that some of the biggest American retailers, including Wal-Mart, Target, Sears and Home Depot, all have said they have no plans to tack on the new fees.