As the holidays approach, more and more people are choosing to give plastic gift cards. Sales this year are estimated at $45 billion, up 15 percent from 2002.

Sounds like a nifty present, doesn’t it? Saves fretting over what Grandma or little Jimmy might like, and it’s a bit more personal than just giving cash. All you do is buy a Visa or MasterCard at a bank or online or one of the special cards issued by such chain stores as Hannaford, Starbucks, Barnes & Noble, The Home Depot, Circuit City and Wal-Mart. Choose the denomination – say, $5 or as much as $500 or more – and the recipient can spend the money until it runs out, with the magnetic tape helping to keep track of the balance.

Banks and retailers find them easier to handle and harder to counterfeit than paper gift certificates. Also, until the money is spent it amounts to an interest-free loan to the issuer. An estimated $4 billion this year will never be redeemed at all. That’s a pretty nice, if unintended, gift, too.

But – there’s often a “but,” isn’t there? – Consumer Reports has been looking into the matter and has issued some warnings. The magazine’s current issue says that some of the cards carry an expiration date or charge a monthly “inactivity,” “maintenance” or “service” fee after a certain period. Wal-Mart’s card, for example, deducts $1 a month after 24 months of nonuse. Hannaford’s card charges $2, but it’s easy enough to avoid if you make even a small purchase within two years. If you lose a card, you could be out the whole amount. Some issuers won’t replace a lost card, and some others charge a fee.

So, whether you are a buyer or a recipient, read the fine print to avoid possible holiday anguish or disappointment.