Hitachi announced[1] a significant step towards localizers[2], with tiny little dust-like RFID tags. Next they need to develop tiny little antennas to match, and then little Diamond Age[3] nanoprocesors.
1. BBC News. "World's tiniest RFID tag unveiled" BBC News Technology
section (online) 2007-02-23.
http://news.bbc.co.uk/2/hi/technology/6389581.stm
2. Mr. Vernor Vinge. Deepness in the Sky. ISBN-10: 0312856830
ISBN-13: 978-0312856830
3. Mr. Neal Stephenson. The Diamond Age. ISBN-10: 0553096095
ISBN-13: 978-0553096095