My passport runs out in 2008, right on time for the UK government's biometric passport scheme to kick in.
I searched google regarding 'passport 2008' and found that as of January 1st 2008, US citizens will require a passport to enter the Caribbean, Bermuda, Panama, Mexico and Canada.
See for more details:
http://travel.state.gov/travel/cbpmc/cbpmc_2223.htmlhttp://www.washingtonpost.com/wp-dyn/articles/A28188-2005Apr5.html