Layar has now available for the iPhone 3GS, after it has been out on Android for a while. Layar is an open augmented reality browser. This means you can have all kinds of information provided by 3rd party developers augmented onto your reality.
I just installed the free Layar app on my iPhone 3GS and it is really a jaw-dropping experience. Even just looking out the window I can use Google local search and see marks where for instance my Pizza joints in the neighborhood are – I can’t wait to get outside to test more.
Thare are all kinds of 3rd party Layars already available like tweeps that shows who is tweeting around you. Other currently available Layers include Wikipedia, London Underground, Las Vegas Casinos, Yellow Pages and many more.
If you have a iPhone 3GS, You should download Layar here now.