BOSTON — Finding a parking spot often requires drivers to summon their inner caveman: Scan the horizon for the target, then bag it before someone else does.

A startup company is betting it can chip away at that anachronism and transform the search for parking just as eBay Inc. changed auctions.

SpotScout Inc. hopes to create an online marketplace where drivers armed with mobile phones can not only reserve private spaces in garages and driveways, but also swap public parking spots in real time, with vacant spaces going to the highest bidder.

Analysts who track emerging online applications say the fledgling venture could successfully capitalize on the growing popularity of mobile Web-surfing and big-city parking frustrations.

But they also question whether SpotScout can make online parking searches sufficiently quick and easy to win over a critical mass of consumers willing to abandon the old-fashioned way of hunting for a spot.

The Cambridge-based company's founder believes there are enough tech-savvy drivers frustrated over parking to make the venture a success.

"In the 21st century, you shouldn't have to look for a parking space anymore," said SpotScout CEO Andrew Rollert, a 32-year-old software engineer. "I hate the term, 'I have to go look for a parking space.' "

SpotScout envisions drivers posting information about their planned departure times and offering the space to the highest bidder. Garages and owners of driveway spaces periodically left vacant also will offer reservations by posting information about times when spots will be empty — a process the company calls "SpotCasting."

Rollert says bidders can avoid doing business with chronic laggards through an eBay-style feature that will allow users to rate their experiences with other users. Those with bad reputations could get shut out. So-called SpotCasters also could earn a poor rating by leaving a public spot early, making it available for any driver to snap up.

SpotScout plans to begin offering test versions of the service this spring by posting information about garage and other private parking spots available for reservation in Boston, New York and San Francisco, with eventual rollouts planned in other large cities. The auction system for on-street public spots won't be introduced until next year.

The 12-employee company is trying to line up its first venture capital deal to finance operations currently funded by individual investors.

But some analysts say mobile Web surfing isn't yet widespread enough in the U.S. to enable SpotScout to quickly build up a broad customer base. Only about 10 percent of U.S. mobile phone customers regularly use the devices for Web access.

"You're not reaching the mass of people who drive around if you use that application," said Charles Golvin of Forrester Research.

Some drivers may find it easier to use new services that rely on wireless technology to find a spot without the complexity of SpotScout's public parking auctions. If SpotScout's application proves cumbersome, drivers could stick with simpler methods.

"There's a certain number of cases where people say, 'I need a spot now,' and that's where a quick user interface is critical," said Golvin.

Said Julien Blin, an analyst at the research company IDC: "I think SpotScout is a good application, but some people might not like the idea of paying for access to a parking spot when they could just find one on the street by looking."

City officials also worry about the prospect of citizens trafficking information about public spots that are supposed to be available first-come, first-served and can't be reserved. Boston's top parking official worries SpotScout customers will gain an unfair advantage over others unaware a public spot is about to open up.