Colin Colby, the Bates freshman who needed a parking space near campus, said he was happy to pay $200 for an answer that came within 72 hours with the name of a woman who had parking spaces to rent. Melissa Mayer, director of product management for consumer products at Google, says the service is still an experiment. A more complicated bidding system was rejected, she said, because of the time involved. "A long bidding process can increase turnaround and decrease the raw efficiency," she said.

Ingenio.com -- a marketplace for legal and career advice as well as answers on business, personal finance, health and fitness, and computing -- sets value a different way. Rather than posting questions generally, visitors can choose an adviser likely to be suited to their problem, then send a query and await a callback. The advisers' per-minute rates for phone consultation are listed. (To try the service, click on Site Map at the bottom of the home page, then click on Live!Advice Directories.)

Chris Camisa, who lives near Chicago, offers technical support to Windows XP users for $1.49 a minute. He takes calls even when he's out at night, by cellphone, if someone "needs support immediately and he's willing to pay for it."

Ingenio helps users choose the best adviser by compiling feedback ratings from past users, like the feedback on eBay. Mr. Camisa's track record of helping people with Windows XP problems, though not unblemished, is impressive: the overall rating from his more than 1,700 customers is five out of five stars.

Not all of the research sites charge. On Wondir.com, anyone can respond to a question, but there is no fee; the site allows those responding to list a PayPal account for tips. In addition, those answering questions can compete for weekly prizes -- this week, a tote bag -- on a changing set of criteria. One week, the winner may have the fastest response time. On another, it may be the person with the highest approval rating. The site derives revenue from text ads, generated by Google, related to the subject of a query.

Matthew Koll, chief executive of Wondir, says the simplicity of the approach means that advice often arrives quickly. The system fields about 10,000 questions a day, and Mr. Koll says about 40 percent are answered within 10 minutes. Why do people take part? Mr. Koll cites three main types of answer providers: people who get "a good feeling out of helping others," those who "have a passion for a subject and they like engaging in a subject" and those with "something to promote." Mr. Koll says he welcomes the last group as long as people are open about their interests. He sees nothing wrong "if someone gets on and answers some plumbing questions and says, 'BTW, if you can't handle it yourself, here's my number."'

Wondir's approach is also different because it makes little distinction in knowledge between the questioner and the answerer. "No one is proclaimed to be an expert," said Michelle Hardenbrook, a moderator on the site. That means, of course, that "anyone can answer any question even if the person answering hasn't got a clue what they are writing or even if the information they are giving is totally inaccurate."