You can set the system to automatically check you into your favorite coffee shop after you've been there for a certain amount of time, or you could use it to tag your parked car to help you find it.
But you can also tag the radio signals of other people's cellphones. Once your phone registers a friend's signal, it will automatically tell you when that friend is nearby.
It's a great feature if you want to meet up with friends for a night on the town, but what happens when a friendship or love affair turns sour?
You may be the type to delete everything related to your ex, but your ex can use your cell's signal to figure out if you're close by.
David Mathews, founder and CEO of NeuAer, put a softer spin on it, saying, "Now you can avoid your exes."
For privacy reasons, NeuAer doesn't save any of the information exchanged between users, so the company can't reach into a user's cell phone to delete the digital signature of another.
But Mathews said the potential positives of the ToothTag system are vast.
"Every radio has a serial number inside of it and we look at that little bit of code coming through the air," he said. The technology is trying "to make your smartphones smart."
Not only is NeuAer launching its standalone ToothTag technology, it also hopes that other applications build on it to make location-sharing even more automatic.
If you're less interested in where someone is than who he's with, a couple of other new applications can help you out.
Last week, Dan Loewenherz, 24, a developer based in Beverly Hills, Calif, made big news in the blogosphere when he launched the Breakup Notifier app for Facebook.
The free app lets users select the friends whose love lives they want to monitor and, whenever they change their relationship status on Facebook, it sends an e-mail.
"You like someone. They're in a relationship. Be the first to know when they're out of it," says the tagline on the app's website.
Facebook pulled Breakup Notifier a few days after its launch, but not before hundreds of thousands of people downloaded it. (Over the weekend, Facebook reinstated Breakup Notifier, after Lowenherz made an adjustment requested by the company.)
"I was blown away," Lowenherz said about the success of Breakup Notifier. "I just thought it would be a fun thing to do. It was going to be a little joke, I was going to send it to some friends? but I think people really like this idea. I just didn't intend it to be this big."
Building on the momentum of his first app, Lowenherz went on to create Crush Notifier, which lets users register a crush and then sends an e-mail when crushes match.
Another Facebook application lets online admirers register their affection anonymously.
WaitingRoom, launched by a couple of "hopeless romantics" who wanted attached friends to know that there were other fish in the sea, lets users "wait" on Facebook friends who are already in relationships.
"WaitingRoom was created in the hope that it would nudge people to find "the One" and to not settled [sic] for a sub-par relationship," the founders told ABCNews.com in an e-mail.
They said they wished to remain anonymous for now because they're "waiting on a couple of friends using WaitingRoom and wouldn't want them to put two and two together if we do an interview."
If you have a crush on someone already dating someone else, WaitingRoom lets you sign up to "wait" for them. The object of your affection gets a notification letting them know that someone is in their waiting room (even if they don't download the app), but they don't get to learn your identity unless they change their Facebook status to single.
Once they've been single for "an extended period of time," they get to unlock their waiting room to see who's inside. (To prevent people from gaming the system, the founders said they plan to change the waiting time randomly.)
Users get a notification e-mail when their crushes change their status to single and when they finally unlock the waiting room door.