Although I can walk bipedally, there has always been some debate about whether Lucy could. John Hawkes provides us with a link to an interesting paper on that issue. The full paper is available Journal of the Royal Society Interface. The authors of the paper applied concepts from evolutionary robotics to an analysis of bipedalism in humans, great apes and Lucy. There is also a quicktime movie - below is a picture from the movie.
Results indicate that A. afarensis was a "fully competent biped." As Hawkes points out, there are several unknowns with the study that need to be addressed, but it was still interesting. Perhaps the most interesting aspect was the application of robotics and genetic algorithms (something I don't know that much about)to the study of human evolution.
When I took Paleoanthropology, my term paper was on bipedality in A. afarensis - I took the position that they were fully competent bipeds - so I was really interested in this article.
On an unrelated note, while checking out the Royal Society website I came across this article on circadian clocks. I mention in case anyone out there, who knows a lot about such things, would be interested in explaining it to us.