Every so often an app comes along that you just get excited about. Well, I'm excited about the Layar Reality Browser [iTunes link], and even better: it's free!

This app has been available on the Android platform, and iPhone users have been eagerly awaiting it. Wait no more.

The Layar app will only run on an iPhone 3GS because it really needs that built-in compass. So what does it do? Quite a lot. The app displays real time information based on your location and the direction you are facing, overlaying the camera with locations and information that you are looking for.

Yes, like other apps with augmented reality, it can find food and shopping, but that's only the beginning. You can find apartments for rent, Flickr photos taken near your location, mountain peaks, tourist information, and the list goes on and on. The Layar screen shows your live camera view, a radar-like display showing you a 360 degree view of 'hits' near you, the accuracy of your GPS fix, and the number of items it has located.

The Layars app is based on an open architecture, so it can interact with an unlimited amount of information set up to talk to the platform. It is globally aware, not just U.S. centric, and lots of 3rd party developers are jumping in.

In operation it generally worked very well. I didn't see any crashes, but at times some of the many servers supplying information did not seem to be up and running. When I wanted to see some information on the mountains in my area, it worked great one time, and the next time it said there was nothing around, even though I was standing in the foothills of some 5,000-foot peaks.

Generally though, the app was well behaved, and as you explore the riches it contains your mind races with all the possibilities an app like this has. You don't have to use only the camera view. You can get a list of nearby points of interest or see everything on a 2D Google map. Wikipedia is even available. When I brought it up, it gave me some information on my town, a nearby school, and some info about nearby parks.

I hope this app really grows, because the potential here is limitless. Try it for yourself. There's no cost, and no risk. You'll be surprised at all the stuff around you. I'm going on a trip soon, and can't wait to explore with Layars.

Let us know how it works for you.