(FORTUNE Magazine) – So you've Velcroed this biofeedback sensor gizmo around your finger to pick up electrical pulses, heart rate, sweat, whatnot ...and on the computer screen in front of you is a slalom course ...and you're the skier, moving fast down the slope. Whack! whack! whack! whack! whack! The virtual you on the screen keeps hitting the slalom gates, one after the other, out of control. Your pulse rate rises. The sensor does its job, picks up your anxiety. Whack! whack! whack! whack! Your task is to weave between those gates, flicking left and right like an Olympian--controlling the image on the screen with nothing more than your mind. That's right: no manual, no joystick, no mouse--just you and your brain and the surface electricity of your flesh and those infuriating slalom gates. Calm down. To master the game, master yourself.

This is the "mind-driven technology" under development at a Sausalito, California, startup called The Other 90%. Now that's our idea of cool: information technology that pushes the limits of possibility, and with a purpose.

In one way or another, the 25 companies on the following pages all mess with our minds, expanding our knowledge, our ability to communicate, our capacity for shared effort. Not all these outfits make money, but that's cool too, so long as you don't invest Granny's life savings in them. To be honest, we kind of admire the way some of these entrepreneurs attract capital to potentially ruinous ventures. Chipmaker Nexgen raised $51 million in its initial public offering in May, despite having lost $29 million in nine months on sales of $8 million. The money's available because the payoff from powerful ideas can be enormous: Indeed, in the three weeks after its IPO, the price of NexGen shares rose 60%.

How do they do it? Technology is essential, but perhaps no more important than common sense: Most of these companies offer products that address real needs. We're dying for AER Energy's 15-hour batteries for laptop PCs. We can't wait to hook up our home computers to the @home Internet-access service, which promises to transmit information 1,000 times faster than we get it now. We love the gorgeous, hand-drawn animation in Humongous Entertainment's CD-ROMs for kids. CKS, Modem- Media, On Ramp, and Open Market are actually helping businesses make some sense of the World Wide Web. Client-server software from SAP America and PeopleSoft makes life at work more manageable. And yes, even biofeedback slalom skiing has a practical application: If you're going to compete in the marketplace with fireball companies like these, you'd better learn how to remain calm under stress.

-Stratford Sherman