One of the unanticipated, annoying side effects of the Internet is how it's managed to jerk phone lines back into the '60s by neutralizing all of the benefits of Call Waiting: Either you turn it off when you dial up to your Internet provider, ensuring that you'll miss that call from your mom, or Call Waiting knocks you offline, ensuring that some multiple-megabyte download will get dropped. Even people who don't use the Internet are affected by this problem, because they often get interminable busy signals while trying to call their Net-obsessed loved ones.

The most direct solution is to get a second phone line for Internet use--at a cost of more than $200 per year. But with all our technology, there ought to be some cheaper solutions, and now there are: a new kind of modem, a special switch and an all-software solution.

Actiontec's Call Waiting Modem (available in internal, external serial and external USB versions) replaces your current modem; when a call comes in while you're online, the modem beeps to alert you. You can ignore the call and keep surfing or pick up the phone and talk, in which case the modem will disconnect automatically. If, however, you hang up within a few seconds, you can keep surfing and keep from losing files you are downloading. But these few seconds are barely enough time to find out who is calling and tell them you will call back. If you need to write down a phone number, you are guaranteed to lose your connection. The modem also did not work properly when first installed, but a call to tech support straightened things out.

Computer Peripheral Systems uses the same approach but different equipment in its Call Waiting Switch, a small, nerdy-looking black box that works with your current modem. It beeps when a Call Waiting signal comes through, then gives you a few seconds to answer, talk and hang up if you want to stay connected to the Internet. This grace period was longer than Actiontec's, but the switch didn't always detect an incoming call, and some calls were also marred by audible modem tones. You also have to wait for about 12 seconds after you hang up before you can redial.

The cheapest and simplest way to get your calls while online is Call Catcher from Pagoo.com, a frontrunner in the highly competitive race to find the goofiest name for an Internet business. Call Catcher, a software-only solution, has nothing to plug in and no modems to change. The catch is, you'll need to have "Busy Call Forwarding" switched on for your line if you don't already have it--and who does? (This option should cost $2 a month and will probably take a week to set up.) When you're online, Call Catcher intercepts your incoming calls, routes them to Pagoo's 800 number, plays your own prerecorded voice-mail greeting, records a message and notifies you via the Web, where you can listen to the message while online. You can even hear your messages while away from home--without long-distance charges--by logging in to its Web site. The software works with both Windows and Macs, but not with many types of phone-company-provided voice mail.

In the end, these solutions may not have a long shelf life. Internet companies such as MSN are building this kind of feature into their service package, although MSN's Internet Call Waiting is not yet available in the Washington area. Ultimately, high-speed, always-on solutions such as DSL and cable modems eliminate the missed-call problem by taking Internet traffic off of your voice line entirely. But while we wait for the interminable, messy broadband roll-out, at least Mom's calls can finally get through to you. And vice versa.

Call Waiting Switch, Computer Peripheral Systems; $100, http://cpscom.com

Call Waiting Modem, Actiontec; Win 95-98, $120, http://www.actiontec.com

Call Catcher, Pagoo, $3.95 per month, http://www.pagoo.com