Global positioning system technology on cell phones is supposed to be a major part of the "mobile revolution." Consider the possibilities. You'll be able to whip out your cell to navigate to the nearest EB, track down your friends all over the city, and even play some wild mobile games based on actual real-world motion. In theory, anyway--as successful as the technology has been in Japan, most mobile LBS (location-based services) specialists in the US market have yet to deliver anything but business plans. This is especially frustrating in the mobile games industry, because the potential of LBS games is absolutely huge, with an unstaunched geyser of schemes ranging from competitive commuting to geocache aids already flooding the market. Part of the problem has been the scarcity of infrastructure on the telco side of the equation: Currently, Nextel is the only national carrier to offer GPS on its handsets--and what is does offer are mostly clumsy Motorola rigs designed to manage fleets of vehicles, not gaming phones. That hasn't stopped a few brave companies, like Glofun of Seattle, from taking the first tentative steps toward LBS mobile gaming in the US. We had a chance to test out its first LBS game, RayGun, on the mall outside San Francisco City Hall yesterday. While we're not about to trade in our flashy new flip phones for a last-generation GPS handset to partake in this simple ghost-hunting contest, RayGun does indeed go a long way toward demonstrating what LBS can do for mobile.

　　The graphics aren't the point here. Besides, who knows what ghosts actually look like?

　　Have you ever suspected that the entire world is filled with ghosts that are trying to close in on you and kill you? If so, and if you're not currently institutionalized, RayGun might just be the game for you! Whip out your Moto GPS phone in an area where you can acquire a GPS signal and walk around safely (that is, not in the middle of a city street), load up RayGun, and get ready to zap. RayGun features a layout that's similar to a radar screen. The dot in the middle is you, and the red, green, and blue blobs heading toward that dot are the ghosts. You dispel the ghosts by turning to face them, walking toward them, and then catching them in your "energy cone" with the action key. RayGun will make a cute zapping sound, and you'll rack up some points. Your energy cone changes its length depending on how far you've moved in a single direction since your last turn, so if you want to zap ghosts proactively, you'll have to walk a ways to get them in your sights. If you're getting overwhelmed by a gaggle of ghosts, you can hit the 5 button to issue a buffer wave, pushing them all toward the edges of the screen. You have a limited number of these lifesavers, though, so it's best to dispel the haunts as soon as you can.

　　RayGun has to jump though a number of technical hoops to get even this simple gameplay model to work. The GPS resolution on the phone we used was three meters, which is approximately four or five steps, and the handset received updates from the satellite system about once a second. The upshot is that it takes a full four seconds of motion before your RayGun cone will update. Glofun encouraged us to think about this problem as simple inertia, but we decided it felt more like lag. Furthermore, you can't rotate the cone when you're stopped. You need to be moving for the satellites to recognize the direction you're facing, because the type of GPS the game uses is based on relative position.

　　Even with these caveats, though, RayGun can definitely be a fun experience if the conditions are right, and if you can stifle your competitive urges enough to avoid walking briskly into traffic while chasing a ghost. Simple though it may be, RayGun is a functioning and reasonably enjoyable GPS mobile game, and that makes it an encouraging sign of things to come. Several US carriers are preparing to roll out GPS services in the near future, and it's starting to look like a few decent games might be there to greet the new technology. Glofun is still looking for a distributor for its product, but with any luck, we'll be able to get nasty on some more ghosts soon.