SAN FRANCISCO – Hoping to make it even easier to turn its online maps into collages of local information, Google Inc. is introducing tools that will stitch together applications from a hodgepodge of Web sites.

The free service represents the Mountain View-based company’s most ambitious attempt yet to capitalize on the growing popularity of hybrid maps known as “mashups.”

In the last two years, Google estimates more than 50,000 mashups have been built on its maps to highlight information about gas prices, running routes, earthquakes, apartment vacancies, home prices and a range of other information.

Until now, the mapping mashups were scattered across thousands of Web sites.

Google is hoping to unite the information mishmash by encouraging mashup developers to package the creations into mini-applications called “mapplets” that will be posted under the “My Maps” section of Google’s Web site.

Multiple mapplets can be laid over Google’s map simultaneously, meaning a user theoretically could get a glimpse at where homes are being sold in a specific neighborhood while also analyzing the area’s recent crime patterns.

“It’s a really powerful innovation,” said John Hanke, Google’s director of maps. “It’s like combining chocolate and peanut butter. They’re good by themselves, but the combination is much more valuable than when they are served in isolation.”

Google introduced My Maps in April to give users a way to save and share their own mashups.

Now, users with Google log-ins will be able to pick from more than 100 mapplets to customize and save their own maps. Google expects the number of mapplets to increase as word about the service spreads. To encourage the phenomenon, Google’s own engineers also contributed mapplets.

Like with most things it does, Google is hoping the new feature will generate more advertising revenue as people spend more time on its site. Advertising already accounts for most of Google’s profits, which totaled $1 billion during the first three months of this year.

The company believes developers will be eager to share mapplets as a way to distribute their own ads and attract more traffic to their Web sites.

Google’s maps attract the third most U.S. visitors in its category, ranking behind rival services from AOL’s Mapquest and Yahoo Inc., according to comScore Media Metrix.