Don't worry too much, all you would-be Mark Zuckerbergs. With some economists citing signs of a possible recession, people following venture capital markets say that there will be some belt-tightening on investments —especially in Web 2.0 and green technology —but it won't be another dotcom bubble bursting.

According to Mark Hessen, president of the National Venture Capital Association , a trade organization in Arlington, Va., clean tech could be the first area to experience decreases in investment because environmental causes usually takes a back-seat during a recession. "Things like clean tech, in many cases, are nice things to have, but they're not required," Hessen says. "If times get more tough, it might be on the chopping block a little more."

Hessen adds that Web 2.0 start-ups could also see declines in funding. "I do think they get affected in the respect that most of those [Web 2.0] companies have a specific agenda, which is to get acquired by companies like Google, Yahoo and eBay."

Even assuming a company like Google continues to invest robustly (and keeps acquiring companies at a rapid pace), Jeffrey Sohl, director of the Center for Venture Research at the University of New Hampshire, says smaller or mid-sized firms will have less to spend on startup acquisitions. That will slow the market for such deals, as those companies would be more affected by a tanking economy. "Those companies are going be affected a lot if we go into recession," he says. "For many investors, that exit [strategy] could dry up."

On the surface, venture capital fund-raising hasn't been this exuberant since the dot-com bubble. According to a recent report by NVCA and Thomson Financial, venture capitalists raised nearly $34 billion in funds in 2007. They haven't raised that much since 2001, when they brought in $38 billion.

If a recession hits, however, it's not clear how much that will affect the acquisition strategies of large technology vendors, which tend to formulate long-term plans for purchasing start-ups or other competitors, according to Alex Cullen, VP and research director, of Forrester Research. Cullen has been researching what a recession will mean to corporate IT spending. "The thing is this: A firm like an IBM, Google or Microsoft doesn't base their acquisition budgets on near-term economic forecasts," he says. "They'd drive themselves crazy if they did."