It's the unfortunate side effect of credit card issuers' fraud monitoring programs. Credit card issuers regularly track their cardholders' purchasing habits and anything out of the ordinary can spark a temporary suspension of transactions. While no one disputes the good that comes from preventing fraudulent transactions, false positives do occur, preventing cardholders' legitimate transactions.

The modern credit cards we all know grew in popularity in the 1950s when banks started issuing them, but the concept of creating a physical object whose holder should be extended credit goes back well into the 19th century. The most common pre-plastic credit instruments were charge plates, celluloid "coins" and charge coins. Here are definitions and examples of each.

When your credit card expires, you probably cut up the card and throw it in the trash without thinking twice. But before you shred that plastic next time, consider tucking it away in a drawer and letting it age; your card may be valuable to hobbyists several years from now, especially if it is a special edition or rare.

Finding out that you've earned enough points from your credit card reward program to jet down to Mexico for free can be gratifying. But if you are trying to figure out which travel reward card you should apply for, it can be a tricky process full of ambiguous language and unforgiving fine print. To assist with your effort, we have dug through the nitty gritty on all of the major reward programs and found where each stands on blackout dates, caps on points earned and expiration dates.

This is the season when frequent fliers' expectations crash headlong into airline realities. While most card issuers assure their rewards-seekers that there are no blackout dates, that's not the same as a guarantee of getting a desirable holiday flight, no matter how many points you have in your rewards account. The truth is, some major airlines allocate all their seats around Thanksgiving, Christmas and New Years for paying customers -- creating de facto blackout days for travelers who've racked up reward points through loyalty programs. Others use "capacity controls" to limit the number of seats available for travelers seeking a free flight. About 6 percent of the seats on an average flight are allocated for frequent fliers using free tickets. So if your holiday plans include using frequent flier miles to take the family to grandma's or a popular getaway, expect a bumpy ride. While there's no real way around this, there are strategies for coping, and making the best of the rewards.

About half of all Americans do at least some holiday shopping online. While buying presents on the Internet beats fighting the holiday mall crowd, it also carries the risk of identity theft and fraud, so new solutions are being created to further safeguard credit card information. Here are some of the best recognized, and safe, online shopping alternatives.

There is a new kind of plastic currency. If you don't play video games, you've probably never heard of it. However, if you have a child or teenager or other video game buff on your gift list, then you need a crash course in "gamer currency," where you pay real money for virtual advantages in imaginary worlds. Gamer currency lets you buys items for use in or with the games, and it comes in the form of plastic "point cards." As often is the case in the real world, the more you spend, the more you get. Want a new "skin" to change the look of your Xbox's Halo 3 game? That runs a mere 150 points. But a Carved Idol Trinket, which provides temporary transformation into a hulking red ogre in the World of WarCraft game? As one would expect, that costs serious points: 25,000.

Not all credit cards are created equal, and comparing credit card offers can be challenging. What is best for one person may not be best for another, so it is important to weigh a multitude of factors, including interest rate, fees, rewards programs and member benefits. Brad Stroh, co-CEO of Bills.com, breaks down some of the most important factors one should look for and compare in a credit card offer.

Beginning Nov. 1, all American consumers gained a new weapon they can use to combat fraud and identity theft -- the credit freeze, which prevents new credit from being issued in their names. All three of the nation's three major credit bureaus recently, and somewhat reluctantly, allowed consumers the freeze option after 39 states and the District of Columbia passed laws requiring it. But while some have said the decision by Equifax, Experian and TransUnion allowing all consumers to freeze their credit files is a step in the right direction, for many consumer rights advocates, the change doesn't go far enough. The credit bureaus' actions enable all consumers to place a credit freeze (also known as a security freeze) on their credit files. Previously, 11 states did not offer their residents the opportunity to freeze their credit files. TransUnion made security freezes available to all consumers Oct. 15; Equifax and Experian followed suit on Oct. 31 and Nov. 1. Their actions should swell the number of people using freezes. According to the Consumer Data Industry Association, a trade group that represents the three credit bureaus, 50,000 to 70,000 consumers currently use credit freezes.

In its final meeting of the year on Tuesday, the Federal Reserve lowered interest rate for the third straight time since September, but put on a poker face about whether it would make further cuts. The Fed's rate-setting group, the Federal Open Market Committee, voted to lower the federal funds rate a quarter point, from 4.5 to 4.25 percent. It was the third consecutive rate cut; in September, the fed funds rate stood at 5.25 percent. What the Fed's Dec. 11 decision means for the size of consumers' monthly credit card bills is up for debate. Ordinarily, consumers with variable rates -- and that's most cardholders -- cheer rate cuts by the Fed. Because banks always peg their prime rates to the federal funds rate, the prime rate will also fall a quarter point, to 7.25 percent.