Like other entrepreneurs, Mr. Devitt says the recent turmoil has changed his plans. Skydeck is now focusing on building features that it can charge for, instead of free services that attract users but not revenue. He also said he would not hire new people until the company hit “certain revenue milestones.”

But not everyone is confident that the Valley is doing enough to adjust to the fast-changing economic situation. Jonathan Abrams, who founded the social networking pioneer Friendster, now runs a party-planning start-up called Socializr, which has only six employees and is prepared to “hunker down if things go bad,” Mr. Abrams said.

Mr. Abrams is unimpressed with the Valley’s readiness in general, saying numerous uninspired, copy-cat entrepreneurs are obsessed with the internal gossip and minutiae of the industry.

“The economy is tanking and people are arguing about whether they should go to Demo or TechCrunch,” two technology conferences that coincided last month, Mr. Abrams said. “Few companies sound like they are breaking new ground. It’s like, ‘Here is Twitter for dogs.’ And people still think they are going to get rich by being a blogger.”

“It seems to me like the industry is still in denial,” he said.