Does your credit card statement hold a place of prominence in your photo album? If you financed your summer vacation with plastic -- and about 40% of vacationers do -- move over the snapshots and make room for your bill. It may be the most lasting memory of your trip.

Credit cards financed almost 40% of summer vacations last year, according to "Americans, Summer Vacation and Debt," a national study by AmeriDebt and Opinion Research Corp. What's troubling about that stat is that more than half of vacationers who put their trip on plastic will not pay it off right away.

With vacationers spending an average of $1,500 on their trip, that's a lot of mai tais and inner tube rentals. Putting just $20 a month towards that balance at an interest rate of 14%, those tan lines end up costing $3,428.43 over the next 14 years. Your card will be paid off just in time for you to put that laser skin resurfacing treatment on plastic!

If you've already taken your cruise/camping trip/Civil War reenactment outing, total your expenses, divide them by 12, and start stashing away that amount to cover next year's summer blowout. If you've already financed your travels with Visa and can't pay it off, negotiate for the lowest rate possible, or transfer the balance to a low-interest card (check out the current rates on The Motley Fool Visa) and pay it off pronto.

And if you're still planning your warm-weather jaunt, keep an eye on the biggest vacation expenses -- hotel accommodations, airfare (see what fares Fools are finding), and Disney doodads.