(FORTUNE Magazine) – Once upon a time, personal computers were deaf and nearly dumb. They didn't respond to voices--a good thing, since we were always cursing their limitations. And they could barely muster a feeble beep if something went wrong.

Windows PCs still won't understand your sputtered obscenities, but they have acquired a far stronger voice. Sound cards, CD-ROMs, DVD drives, and MP3 files have all conspired to turn the utilitarian desktop computer into a decent--and often loud--entertainment machine. That's why I've found myself playing the audiophile in recent weeks. I've been testing two new sound systems designed for the PC. The products, one from Yamaha and the other from Creative Labs, are actually sophisticated stereo systems that add muscle and quality to the PC's sound, transforming the relatively weak signals from the sound card into juice that can drive a decent set of speakers.

If looks matter to you as much as sound, the Yamaha RP-U100 Personal Receiver ($499) literally stands out. The stylish silver box, about the size of a standard stereo receiver, is designed to sit vertically alongside your PC. Its face cants back rakishly at the angle of a laptop screen.

This full-featured stereo receiver generates 30 watts of audio power per channel, enough to rattle the mouse and telephone on your desk. The built-in AM-FM tuner can be preset for 40 stations--and up to 200 if you use Yamaha's software. Once connected, the RP-U100 will amplify any sound emitted by your PC: from the bleeps and grunts of the system warnings, to downloaded digital media and the audio from CDs, CD-ROMs, and DVD movies.

Working with just two speakers (not included), the Yamaha attempts to emulate the 5.1 Dolby Digital standard, the six-speaker "surround" sound scheme used in home theater systems. Yamaha's virtual version makes a credible--if not altogether convincing--effort to fool you into believing a two-speaker system sounds like six.

Setting up the Yamaha wasn't difficult. It easily connects to the computer through the USB port. My only problem was the receiver's expectation that speakers will be attached using standard two-wire stereo connectors instead of the RCA plugs on my cheap PC loudspeakers. Maybe it's a form of quality control, since most quality speakers don't use RCA plugs. (If your speakers do use RCAs, you can clip them off one end, strip the wires, and attach them to the Yamaha.)

Whether you're hooking up to a Mac or a Windows PC, the Yamaha's large-knobbed front panel allows you to control the system. Windows users can also control the system from their PC, using refreshingly straightforward software provided by Yamaha. That allows you to use your PC's keyboard to type in the frequencies of your favorite stations and then tune them in with a single click. You can select one of six surround-sound ambiances, which alter the sound to make it seem as if you're listening in a concert hall, for example, or a church. You can also adjust the sound to fit your speaker layout and the characteristics of your room. And you can choose from several alternate sound sources, such as a DVD player.

It's probably unfair to call Cambridge SoundWorks' Desktop Theater 5.1 DTT 2500 Digital the ugly duckling of this review. But compared with the slick-looking Yamaha, the small, black control unit for this PC sound system is rather nondescript. However, it was a lot easier to find a place for the DTT's little box on my crowded desktop than it was for the Yamaha.

For just $299, Cambridge SoundWorks, owned by PC sound expert Creative Labs, sells a full-fledged Dolby 5.1 home theater setup--including six speakers. The five front and rear speakers are black 3 1/4-inch cubes, and the bass unit is just eight inches high. My biggest challenge was assembling the tripod stands for the rear speakers.

Despite its compact size, the Digital DTT system delivers a big sound. It is especially effective with DVD disks and games, which often use the Dolby Digital standard. When you watch a film, sounds move left to right and front to back, just as they do at better movie theaters. If you use the system with a Creative Labs sound card (the No. 1 brand) and software--once again, available only for PCs--you have a wider range of ambiances, tweaks, and features. Like the Yamaha, this system will also upgrade a Mac's sounds because basic functions can be controlled from the box.

Neither desktop sound system can compete with a high-end stereo. But they both cost a lot less than the high end, and they raise the ante for PC sound quality. These products offer clean, accurate sound--stringed instruments sound lush and real, and you can easily tell the difference between brass instruments and synthesizers--and they can be cranked up enough to disturb your neighbors. If you or your children play games, better sound adds a level of reality that can make gamers sweat or soar. No doubt about it, PCs have come a long way from the days of green screens and the occasional beep. Where did I put my earplugs?

Scan Those Business Cards

No matter how high tech we become, old-fashioned business cards continue to survive. I've been known to magically "zap" my business card, using infrared technology, to another nerd with a Palm Pilot, but it takes two Palmists to do the infrared tango. So most of the time I still have to go through the painful process of typing in the data from those little pieces of cardboard.

Corex has built a nice business by alleviating that annoyance. Its CardScan Executive is a compact scanner that reads business cards and transfers the data into the major desktop organizers. The most recent version, the CardScan 500 ($299) now offers a USB connection--eliminating a source of problems when CardScan tried to share the printer port with some finicky printers. Corex has also upgraded the look of the small, black device, giving it a more contemporary styling.

But the real value is CardScan's software, which has improved. It now recognizes foreign languages and phone numbers and smartly moves the data into the right spot in your Palm, Microsoft Outlook, Lotus Organizer, Act, GoldMine, or Lotus Notes address book. It will also work with Windows CE devices, Psion palmtops, and digital mobile phones.

Occasionally, CardScan gets confused by a logo or baffled by an ornate card from some over-the-top dot-com. However, you can quickly go into the data and make corrections. It still beats sitting at your PC and inputting that stack of cards from your last business trip.