Argh! In 2001 or 2002 I suggested developing this to my then PhD supervisors (for portable heritage information) and they could not see the point! http://www.nzherald.co.nz/travel/news/article.cfm?c_id=7&objectid=10626716

And if you think this is science fiction, try out this for size: http://www.google.com/mobile/goggles/#landmark