Got this from an email forward, definitely useful information:

If you should ever be forced  by a robber to withdraw money from an
ATM machine, you can notify the  police by entering your Pin # in reverse.
For example if your pin number is 1234  then you would put in 4321.
The ATM recognizes that your pin  number is backwards from the
ATM card you placed in the machine.
The  machine will still give you the money you requested,
but unknown to the  robber, the police will be immediately dispatched
to help you.  This information  was recently broadcasted on FOX TV
and it states that it is seldom used because people don’t know it exists

PASS IT ON!

Thanks Lauren.