The summer 2005 issue of Expedition features an article on the 2002 experimental journey across Lake Titicaca in a recreation of a Peruvian 'totora' reed boat:
"Reed Boats and Experimental Archaeology on Lake Titicaca" by Alexei Vranich, Paul Harmon, and Chris Knutson -- freely available as a PDF file. An earlier article by Paul Harmon appears on the Archaeology magazine web site.
The experiment was designed to answer the question posed by the monolithic stone architecture of the Incan city of Tiwanaku: How might the stones have been transported from the quarries situated across Lake Titicaca? A nine-ton andesite stone was located, transported to shore and loaded onto the recreation of a reed boat, built purposely for transporting the stone.
A full account of the project appears on the project's Qala Yampu web site, including biographies of the participants, a "Captain's Diary" of the voyage, and links. At this writing a documentary film on the project is near completion, but no air dates have been set.