Perhaps this is old news, but it sure sounds like a good thing to me.
The Gummint is now issuing a wallet-sized version of the passport for
$20 if you already have one. It sure would simplify ID at airports and
Immigration and Naturalization ports.
http://www.usatoday.com/news/nation/2008-07-20-passport_N.htm?csp=34

Can anyone identify any drawbacks that aren't apparent?

A group of us will be going on Carnival Conquest at the end of
September. First stop is Montego Bay and some of us were wondering about
taking one of the rafting tours. There are two offered, one is 3.5
hrs and the other 4.5 hrs. Just wondering if there is really any difference
in the two other than the hour, or if either trip is worth taking. Any info
will be appreciated.
Thanks,
Ray Bensch

Thanks to everyone who replied to my request. The information has been
helpful.