SLAM, if you are too lazy to read the wikipedia article and prefer to learn this kind of stuff from a blogger, enables the device to locate its position in a pre-scanned room while continuously update its stored map of the room, all this without using markers. Here's a cool demo from Oxford, showing SLAM assisted augmentation of a museum, which suggests one way this technology can be used. Another scenario may be something like an ikea store where using an iPad you could change the color of the sofa which is right in front of you (or locate the exit).
This lead me believe that with some luck 13th Lab may become a force to be reckoned with in indoors AR. Moreover, 13th Lab aims to be a platform provider, like, well, Layar (and admittedly, many other companies in the AR space).
Writes Petter Ivmark, one of the founders:
If you buy into their vision, you can sign up to their developers network. Better yet, if you live in Sweden, they are hiring - I bet it's going to be worthwhile to join them.