He said that in passing, and it seemed so absurd that I had to find out more. So after his talk, I went up and asked. Woz explained that he was participating in an expedition planned for December 2007 in which a group will drive Hummers running on hydrogen powered fuel cells from McMurdo Station to the South Pole. 

Woz said his particular vehicle would be co-piloted by Buzz Aldrin, who walked on the moon in 1969. 

The expedition is to be filmed in 3D for the director James Cameorn. 

Woz said that the group has received important advice on the project from the Santa Clara Valley Transportation Authroity, which has been running some hydrogen fuel-cell powered buses.