through one of the earlier links to (I believe) the lightweight panniers, I came upon this link to a trip video made by some guys who biked in Alaska, on Pugsleys, along with inflateable rafts that they plopped their bikes onto to cross areas they couldnt bike along the shore.

pretty darn hardcore, neat to watch though, so in case you didnt see it:

http://vimeo.com/25943565