I was listening to episode 187 ["on an undercover cop"] of BinRev today an got struck by an idea:

What if people started using RFID tags for something useful for a change and put them [at the very least] in high-traffic areas to aid those with disabilities [especially blind persons] by providing an identifier for street signs, crosswalks/traffic lights etc? From my Google research it seems that these could be used for additional applications to further justify the cost of implementing the system. The people in question would simply carry around an RFID reader that will scan and receive the ambient tags; it can then process it in a number of ways to generate speech regarding the surroundings [harder to do with street names but relatively trivial with signs, for example.]

Wal-Mart has already implemented a similar system for its stores. I believe there is a lot of possibility to extend this into the streets - start with those areas that have so much traffic volume that makes it hard to ‘navigate’ for guide dogs.