When David Yang recently looked for a new apartment in Chicago, he took an aerial tour of the city.

As a 22-year-old on a limited budget, Yang couldn’t afford to hire a helicopter for his visual inspection of Chicago. Instead, he turned to HousingMaps, a hack that combines craigslist real estate listings with city maps from Google Maps. It lets users pinpoint locations, along with one-click access to photos and descriptions, of dozens of available apartments in more than 20 North American cities.

“It’s like flying around the city looking at real estate,” said Yang, a consultant for Deloitte. “If I know where my friend lives, or I know where an El (train) stop is … I can just zoom in and see what’s convenient to me.”

HousingMaps, created by Paul Rademacher, a 3-D graphic artist from Santa Clara, California, is just one of several innovative hacks giving users new ways to use information since Google launched its maps service. Google Maps offers detailed maps of nearly anywhere in the United States or Canada on which users can quickly zoom in or out.

These simple but powerful hacks are not exactly authorized. Google has not offered software tools and licensing terms for developers to work with its mapping engine and data. But the hacks nevertheless offer a compelling glimpse of what’s possible when online data plays well together — a major goal of internet-standards initiatives such as XML that, for the most part, are still a work in progress.

HousingMaps is an eye-opener, offering a simple and easy-to-navigate interface that lets home and rental shoppers take in a neighborhood of offerings at a glance, complete with locations, prices and, in some cases, pictures. Even with the extra data, maps rendered smoothly when we tried them on Thursday.

Hackers have also meshed Google Maps with sites like the photo-sharing service Flickr, Yahoo’s traffic notifications, city transit maps and others.

Google said it doesn’t comment on other websites.

But Stewart Butterfield, a Flickr co-founder, said he thinks Google Maps is a natural service for tech-savvy developers to want to use as the basis for experimentation.

More here.