*Hey, Waiter, Where's my check for the soup?* No worries, sir, we're scanning your stomach as you walk out through the doorway and will bill you directly.
Okay, that's a little much, but I also thought that the movie "Minority Report" was a little much until I realized that it featured RFID technology.
Anyway, Hitachi has made some incredibly small RFID chips. How small? Compare.

On the left is a small RFID chip-on the RIGHT is a human hair surrounded by these powered RFID chips.
Think of the possiblities of how these can be incorporated.......