(FORTUNE Magazine) – You're a dirt-under-the-toenails Silicon Valley technogeek, and you've just come up with an idea that's sure to reap billions--or at least a quick hundred million. But before you make the rounds with your dog-and-pony show in search of venture capital, here are a few suggestions: (1) Buy a suit, (2) get a pedicure (we know no one will see your toenails because you will be wearing shoes, but it's the principle of the thing), and (3) enroll in the Workshoppe, Silicon Valley's first and only finishing school.

Sure, Silicon Valley is the one place on earth where you may get your venture capital even if, like some Workshoppe neophytes, you have a tendency to lick sauce off your knife during business lunches. But why chance it? Invest about $150 on a Workshoppe, and as you and your fellow Webheads dine in one of the Valley's premier restaurants under the expert guidance of former Apple marketer Sue Fox and retired British fashion model Lyndy Janes, you just might learn enough to not blow that big deal.

Janes--who does most of the actual teaching, leaving Workshoppe's business side to Fox--knows that when you're teaching table manners to the Java-and-HTML crowd, the instruction must be, well, remedial. That suits everyone just fine when FORTUNE attends a Workshoppe at Zibibbo, the earth-toned, sky-lit restaurant of the moment where Chelsea Clinton goes when she needs a break from the mystery tofu served in the dining halls of nearby Stanford. Indeed, even before our classmates--most of whom come from software publisher Adobe--show up, Janes knows she has her work cut out for her. "It's an etiquette class," she says, glaring at her watch, "and people are late."

Once the stragglers are finally seated, Janes begins coaching us through every part of the meal, from the bread ("Don't twist off a big piece like you're wringing out the laundry") to the finger bowl ("It's for your fingertips only, so please don't plunge your hands all the way in"). Between courses we cover the basics of mealtime etiquette, like excusing yourself discreetly when nature calls. "We don't need to know about your potty runs," says Janes. "And ladies, do you really expect anyone to believe that you're going to 'powder your nose'?"

Workshoppe students provide ample fodder for discussion by making blunders that get pointed out to the rest of the group. First, there's the guy who does an exemplary job of excusing himself from the table discreetly, only to leave behind his cell phone--ringer on. Minutes later an Adobe saleswoman grabs a serving dish of palate-cleansing sorbet, puts it on her plate, and dives right in as if it's the latest flavor from Baskin-Robbins. "Giant faux pas," says Fox.

Even though they were hardly A+ students themselves, the Workshoppe's attendees gave the evening high marks. "I think a lot of the companies here are moving beyond the startup mentality," says Liz Quinn, a compensation specialist with Adobe and two-time Workshoppe attendee. "This is the perfect thing to help people grow up a little."

In addition to helping technophiles at dozens of companies--including Sun, Netscape, and AT&T--Janes and Fox do a brisk business in private lessons for those too bashful to ask which fork to use in front of their colleagues. They've also got a new line of videotapes, covering every aspect of geek etiquette from social skills to formal table settings. But this duo of 40-something divorcees is already suffering from one big downside of success: "We don't get many dates anymore," laments Janes. "Men are terrified that if they take us out to dinner, we'll spend the whole meal correcting them."