High-tech stocking-stuffers.(Sight and Sound)(includes list of phone numbers / web addresses for products described)

Like live animals or expensive gym memberships, high-tech gizmos deserve their own category as over-the-top gifts for the holidays. They have similar responsibilities for the giver, too: know your audience, brush up on the technology, and get a good deal. Whether it's wrapped in aluminum foil or in Tiffany blue, the right electronic gadget can generate more excitement than the bijoux on Marguerite's doorstep. What follows are ten examples of futuristic technologies, almost all priced under $100, to fit every taste and style.

First, who's the intended recipient of your largesse? Hardcore opera buffs seize any available moment to catch a snatch of song--on the treadmill, in the shower, under the car. When choosing a portable CD player, make sure it plays both conventional CDs and discs created on a home computer. The PSA[cd12 ($100) from Nike, for example, plays CD-R media or home-brewed discs that you've mixed from several different CDs. What's more, the device is compatible with the MP3 format, which allows users to pack more music onto one disc--you can play a disc more than six hours long without cracking open the player to change it.

For listening on the road, it's important to be able to connect your new CD-R or MP3 player to the car's stereo system. Most car radios with CD players don't have the ability to play the new formats, but using the TuneCast Mobile FM Tuner ($39.99) from Belkin, you can hook in your portable player wirelessly. Simply plug the little Belkin into your device and tune the car stereo to a designated radio station. (The classical station is usually a few ticks south of NPR at the bottom of the dial--but you know that already.) The device sets tip a small wireless zone around your car, beaming clear music to the sound system.

For a combination of hydrotherapy and great acoustics, few spots in the house beat the shower. But most CD players aren't waterproof: The lime-colored ICF-CD73VLIV Shower Radio ($79.95), from Sow's high-design LIV home-electronics collection, functions as a sturdy, easy-to-use shower CD/radio, with an eye to the future. Though it won't play MP3-encoded discs, it will drive your home-recorded CD-Rs. You may not want to keep your greatest hits handy on the shampoo rack, though.

Out of the shower, a good pair of headphones makes music more personal, allowing one to enjoy full volume without facing a rash of complaints from family members. There's no better way of keeping a symphony to yourself than the Sennheiser RS 30 ($99.95) wireless headphones. These use radio frequencies to connect the lightweight phones to your home-stereo system, up to 50 feet away.

Does anyone on your holiday list keep a suitcase packed at all times? For inveterate travelers, the best headphones are those using active noise-cancellation technology. This feature--designed to squelch the enervating drone of jet engines on a transcontinental flight, for example--has been in high-priced sets for some time. A good buy right now is the Philips HN 100 ($69.99), a fordable headphone set that comes with universal adapters, so you can enjoy superb sound while watching airplane movies.

For globe-trotters who plan to take photos on a trip, there's nothing better than a digital camera. The problem used to be that you had to pay a lot for a camera that would deliver a quality image. The Eye-Q 3040 from Concord Camera ($129), however, is a digital with a 3-million-pixel sensor at an affordable price. The shooter captures more visual data per photograph, making snaps look as good as prints at the 4-by-6 size.