Here's a really impressive demo of the Tab doing Augmented Reality using a standard poster as the target:
VIDEO: http://www.youtube.com/watch?v=XAAxb3GqaYs

I've seen it done with symbols, though with a standard poster is quite impressive. I do wonder, however, if its tracking the flower pattern or the white border...

Either way, it's quite smooth. My only complaint is that the projection isn't fixed very well to a specific portion of the poster.