A backlash of sorts has been forming against location-based services, one of the hot new social categories. Despite the popularity of services like Foursquare and competitors like Gowalla, some have argued that these tools won’t scale. After all, the argument goes, just how many people do you really want knowing where you are at any given time?

It’s a short-sighted observation. There’s far more to location-based social media than checking in so the world can know you’re at the grocery store. (Besides, who really wants to be the mayor of Safeway?)

Justin Davey, author of the GPS Obsessed blog, joined the throng of bloggers offering up their predictions for 2010, although Davey’s forecast was focused on geospatial industry trends. He sees an explosion in the use augmented reality and mobile coupons. He envisions search engines dishing up location information with search results and the same time of location-based information appearing with videos shot with GPS-enabled devices that you can now find on photos uploaded to sites like Flickr. And, he writes, every gadget—from digital cameras to netbooks (and, presumably, tablets)—will include a GPS chip.

One of the more interesting location-based sites, though, doesn’t take advantage of a GPS chip. At least, not yet. GroundMap was launched by a pair of 20-somethings from Poplar Bluff, Missouri, with an eye toward becoming the next big social media destination. Whether they’ll reach that goal remains to be seen, but GroundMap does point to the growing importance of location-based content.

“The Internet is located somewhere nobody knows, and we’re essentially making it relevant to where people go,” co-founder Matt Boyd said in a Southeast Missourian interview. “We’re almost making digital media tangible.”

GroundMap lets you associate content—tweets, documents, YouTube videos, Google Maps, you name it—with a place. If the location you’re interested in isn’t listed, you can add it. You can also add your opinion to any content that has been contributed.

Checking Rockville, Maryland—one of the most popular places listed, according to the tag cloud that appears on the home page—I found a couple YouTube videos (including one of an all-GM car show that was held in town), a link to the wikipedia listing for Rockville, a photo of city hall and a few other links and opinions.

The site is brand-spanking new, launched the last week of 2009, so there’s not a lot of content yet. But it’s easy to envision city listings loaded with material. The potential for marketers—particularly for small businesses—is huge. I’ve already read one account of the owner of a resort uploading a PDF of information about the facility to the listing for the city where the resort is located.

It makes perfect sense. Given our increased reliance on peer content, this would make it easy to learn what others think about a city to which you plan to travel. Sure, there’s Yelp, but it’s limited to reviews and you have to know the name of the service you’re researching. There’s CitySearch, but it’s limited to the major metropolitan areas and user-generated content is limited to reviews of services already listed. And while much of the content associated with a city in GroundMap already exists elsewhere (such as YouTube), it would take a lot of work to uncover it with a typical web search.

GroundMap will be a lot more useful with a bookmarklet that lets you add content from anywhere on the web, an iPhone app that adds GPS functionality, and other enhancements. But the obvious benefits of the site underscore the growing importance of location-based services. PR and marketing professionals would do well to begin exploring the opportunities these sites have to offer.