Tomorrow's cell phones (and Palm Pilots, GameBoys and MP3 players) will be wired for high-speed Internet. But that doesn't mean they'll access the same graphics-heavy Internet that you've got on your computer right now. Those tiny little handset view screens make that impractical.

So tomorrow's wireless killer apps will be things that can be cooked down to concise alphanumerics. Cyberporn is out, in other words, and real-time stock trading, instant messaging and interactive coupons are headed for liftoff.

To understand how this changes things, pretend you run a restaurant in New York City. Because cell phones send out signals that pinpoint a user's location, you'll soon be able to post 15%-off coupons on every handset within a 10-block radius.

Or say you're in your car and your Palm Pilot notifies you that Andy Grove just filed to dump his entire stake in

Intel

(INTC) - Get Report

. You see this, press "sell," and you're out before nonwired investors know what's about to hit them.

And these are just the things we can envision today. History teaches us that the real killer apps will be totally unexpected. The only certainty is that they'll be limited by the size of handheld viewing screens.

This creates a huge, brand-new market for two groups of companies: The creators of next-generation content and the "enablers," who help other companies make their content wireless-friendly. The first group is in its infancy (though I'm trying to round up some suspects, so by all means send in your picks). But the second is already hot, with some likely winners starting to emerge.

Aether Systems

(AETH)

, for instance, started out designing real-time stock quote and trading systems for handheld devices. Its TradeRunner service is available now to brokerage customers of

Morgan Stanley Dean Witter

(MWD)

. Soon it will be available at

Charles Schwab

(SCH)

, giving Aether access to the biggest single pool of online traders. Also big is a recent deal to make data from financial information powerhouse

Multex.com

(MLTX)

available on Palm Pilots and Blackberry units (the hot handheld in the trading community) by the end of the year.

Beyond finance, Aether is into health care (linking doctors to pharmacies, for instance), sales force automation and transportation logistics. And through a joint venture with

3Com

(COMS)

, it's going after wireless email, among other things.

And

it's creating a venture capital portfolio of development-stage wireless content companies.

Approaching from a different part of the field is

InfoSpace

(INSP) - Get Report

, which started out offering other Internet companies instant content, like maps, phone directories and weather reports. As a result, its customer base reads like a Who's Who of cyberspace, with names like

America Online

(AOL)

,

Microsoft

(MSFT) - Get Report

and

Lycos

(LCOS)

.

Now it's making the logical migration to wireless, cutting deals with cell phone giants

Verizon

(VZ) - Get Report

and

AT&T Wireless

(AWE)

, through which it supplies the default platform for wireless consumer services. The carriers pay InfoSpace $1 to $3 a month per subscriber, which, given the growth potential here, could amount to a serious chunk of change in a few years.

Others to check out include:

724 Solutions

(SVNX)

, developer of a platform that lets banks offer secure online services over cell phones and their kin. It's partly owned by

Bank of America

(BAC) - Get Report

,

Citigroup

(C) - Get Report

and

Bank of Montreal

(BMO) - Get Report

, and is creating "portable banks" for Bank of America that will let high-end clients check balances and move money using wireless handsets. If this works out, real-time trading will come next. Other big customers include super-regional bank

Wachovia

(WB) - Get Report

,

BBVA Bancomer

, Mexico's largest bank, and online billing leader

CheckFree

(CKFR)

.

Datalink.net

(XLNK)

, developer of patented technology that makes high-speed data feeds wireless-friendly. A couple of recent deals illustrate the breadth of this market. In August,

On Time Media

, a logistics firm, licensed Datalink.net's wireless technology to track freight wirelessly. A week later,

NetCurrents

(NTCS)

, which specializes in turning complex real-time market indicators into simple graphics, partnered with Datalink.net to bring this content to its wireless subscribers.

So are these stocks buys? That depends on how comfortable you are with the whole priced-for-perfection valuation model. Despite trading way off its recent high, Aether's market cap is $5 billion, more than 200 times its trailing 12-month sales of $22 million. InfoSpace is worth $9 billion, vs. sales of $68 million, with the other two companies mentioned here in the same ballpark. All are growing at triple-digit rates, so the disparities will shrink over time. But as volatile as bleeding-edge stocks tend to be, there's a good case to be made for waiting until the next big correction before getting in.

John Rubino, a former equity and bond analyst, is a frequent contributor to Individual Investor, Your Money and Consumers Digest. His first book,

Main Street, Not Wall Street, was published by William Morrow in 1998. At time of publication, he had no position in any stocks mentioned. While Rubino cannot provide investment advice or recommendations, he invites your feedback at

jrubino@thestreet.com.