casey chesnut has been \<a href="http://www.mperfect.net/blog/browse.aspx%3fbid%3d633261847266875000"" target="_blank" rel="noopener noreferrer">playing around with augmented reality for the UMPC. I think he's going strictly for a technology demo, but the physical tags he's constructed seem to be about the right size for a conference badge. That'd be kind of cool -- hold up your UMPC in a crowd and get a "magic window" collection of homepage URLs?