This is shaping up to be LBS day here @ Mobile Marketing Watch, as a brand new LBS service just made itself known to us.

GroupTabs, a brand new startup out of NYC, has built a service that allows users to “check in for deals,” and is asking the question; “what if Groupon made sweet love to Foursquare?” (This was also the subject line of their email to us, which was too awesome to pass up).  As you can imagine, the service aims to combine the power of group-based deals (Groupon) and the check-in functionality of Foursquare, to provide a unique new LBS solution.

Here’s how GroupTabs itself explains it’s new service: “Pardon the clichés, but we’re not reinventing the wheel, we’re just putting it on a different car.  Every day we offer up a deal at a bar or restaurant in New York City.  We let our members know on our website, our email newsletter, and on gtb.me, our fancy HTML5 mobile app (we’ve got native apps in the pipeline).  If you want, you RSVP, letting your friends know that you’ll be at that night’s deal.  Every deal has a window, usually a couple of hours.  Let’s say people start checking in.   They enjoy the regular special.  The deal tips once the required number of people check in.  You show your server the redeem tab of our app.  You and your friends enjoy your deal.”

When asked “why did you build GroupTabs,” the company responds with “Checking in is addictive.  Being the mayor makes you feel special…if you’re into that kind of thing.  But what about everyone else who wants to check in and get something special?  Why reward only one person, or every 10th person.  We figured that there had to be a better way to do the whole ‘monetize the location based services thing.’  So we asked ourselves who knows how to make money right now?  Groupon.  And that led us to our class project: What If Groupon Made Sweet Love To Foursquare? The answer is GroupTabs.”

The startup definitely has potential, and is launching next month in New York City, with plans for expansion in the near future.  The company seems to be taking things slowly, which is probably smart given the onslaught of new LBS apps and services that are launching everyday it seems.  The startup will launch with its HTML5-based Web app, but says native apps are on the way.  What’s interesting is that GroupTabs will aim to become a unified check-in service as well, by checking you in to other LBS services when you check-in via GroupTabs.  ”If you’re already using foursquare we’ll check you in when you make your GroupTabs check in. We’re looking at Gowalla, Brightkite, Loopt, and the other guys, but starting out with foursquare makes sense for us here in New York City. We’ve also hooked GroupTabs up to Twitter and Facebook.

We’ll definitely be keeping our eyes on this one.  If you want to too, check out their infomercial located on their homepage, or follow them on Twitter.  There’s also more information in the form of a Q&A located here.