This week Schechner’s wait will be over. After more than a year of ultrasecret preparation, Handspring will introduce Visor, a sub-$200 handheld computer that runs the Palm operating system and features an innovative expansion slot designed to accommodate add-on modules like digital cameras and music players. Though the company is backed by the top venture capitalists in Silicon Valley, its biggest asset is the legacy of its founders. Hawkins, the product visionary, and Dubinsky, his operational field marshal, jolted the handheld market back to life after flops like the Apple Newton flat-lined in the mid-’90s. Since then, 4 million Palm Pilots have been sold–and not all to professionals. This year the Arcadia school district in L.A. had to warn all its high-school students against beaming answers between Palm Pilots during exams. Though the Visor looks similar to the Pilot, Dubinsky says it “marks the next step in the evolution of handhelds.”

Like its Palm brethren, Visor is essentially an electronic organizer. It allows you to manage your contacts and calendar, and synchronize them with your computer. It costs $179 for a basic unit or $249 for a flashier model with more memory. (Units will go on sale on Tuesday at www.handspring.com, but won’t be in stores until early next year.) Both are cheaper than their closest cousin, the Palm III, though 3Com is sure to lower prices. Handspring’s step forward comes with the two-inch-wide slot in the back of Visor, dubbed “Springboard.” The company says that in the next few months users will be able to buy modules of various shapes and functions, including a pager, an MP3 music player, game cartridges–even one that converts the unit into a cell phone.

Analysts are mixed on whether consumers will really embrace a “Swiss Army knife” approach to the handheld market. But all are impressed at how Dubinsky and Hawkins have so quickly created a company sure to be a major force in the nascent handheld space. It was only last summer that the pair resigned from 3Com, after the networking giant refused to spin out Palm Computing as a separate company.

That same week, Hawkins retreated to his Silicon Valley home to figure out what their new company would sell. His father was a Long Island inventor who once built a floating stage for a Pittsburgh orchestra and took his family on tour with it–so Hawkins was raised to be a tinkerer. Toiling in his kitchen, he started to think about how to retrofit Palms to play the MP3 audio files that were gaining popularity on the Web, and hit on the idea of a hardware slot that could accommodate any kind of add-on device. After fleshing out his idea in his black leatherbound notebook, Hawkins built a model of the Visor out of wood in his garage.

And so Handspring was born. This Tuesday’s announcement marks the first salvo in a master plan to introduce at least three new Handspring products in the next few years. “I’d like to get to a billion dollars [in revenue] as fast as anybody has ever done it,” says Dubinsky. There are other signs of the founders’ aggressive strategy. Every year Dubinsky, Hawkins and their longtime marketing VP, Ed Colligan, go to dinner together to celebrate their success. The founders say next year’s dinner is tentatively marked in their Visor calendars for January in New York City–where they hope to be prepping for a Handspring IPO.

Cartridges for the Visor give it a versatility that could vault it over the Palm:

VideoGames: Tiger Woods golf from Electronic Arts is available this week, with several other titles to come Cell Phone: The cartridge includes the earpiece and antenna, while the microphone is built into the Visor. Coming next year. Modem: Plugs into a phone line for access to the Net. A wireless modem is planned. MP3 Player: Download music from the Web, then play it on your Visor. By Diamond, maker of the Rio. Two-Way Pager: The Visor’s large screen lets you see who’s calling and easily tap messages back