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If you're still poking along in the slow data lane with a 33.6-, 28.8-, or even 14.4-kilobits-per-second modem, it may be time to get in the express lane with a 56-kbps modem. These devices don't actually transfer data at that speed, but if your Internet service provider supports them, they will be faster than what you've been using.

Cutthroat competition has driven modem prices into the cellar. Bargain 56-kbps units are available for as little as $100; most are in the $125-to-$200 range. Higher-end models add extras like voice mail and speakerphone support. (All modems can send and receive faxes these days.)

Initially, 56-kbps modems used one of two incompatible specifications: x2 and K56flex. At press time most ISPs supported only one spec--and on relatively few dial-up lines. This situation should change rapidly following the creation of a single v.90 international standard, defined in February and expected to be formally adopted in September. Modems supporting the new standard were just beginning to ship as we went to press. Additionally, all modem suppliers have promised that users can upgrade their older 56-kbps units to the final standard.

But here the devil, as usual, is in the details. Some companies promise a free upgrade, while others say they'll charge a nominal fee. You can upgrade some modems by downloading and installing new firmware from the Web; other units will have to be returned to the vendor for upgrading. (For updates on these issues and on ISP support, visit www.v90.com.)

Among major modem suppliers are 3Com, Boca Research, Cardinal, Diamond Multimedia, Hayes, Logicode, Motorola, Practical Peripherals, and Zoom Telephonics.

It's hard to predict actual data speeds for a 56-kbps modem; most users can expect downloads in the 40-to-50-kbps range. Even in ideal conditions, downloads can't exceed 53.3 kbps because of a federal rule limiting the top speed on dial-up lines to this rate. The data you send is also constrained by technology to 33.6 kbps max, but that isn't a big problem in typical Web sessions, since you download most data.

Also, 56-kbps modems are extremely fussy about the quality of phone lines. Especially if you live in a rural area far from a central telephone office, lines can get noisy; a phone line that sounds fine to you may be terrible for moving data at high speed. And in metropolitan areas, telephone companies often combine multiple phone sessions on one channel, which can put you back in the slow lane. To pinpoint where traffic really jams up throughout your Web connection, try VitalSigns Software's Net Medic (download a free trial version from www.vitalsigns.com).

Once you get under the hood, installing a 56-kbps modem isn't much different from installing any other modem. Here's how to do it.