So unless you've been living under a rock for the last two weeks (well, or you don't follow the science news at all) you would have heard about Ardi (a female Ardipithecus ramidus), who is the oldest known hominid and a possible human ancestor. Ardi's remains and her likely habitat was analyzed in detail in a Special Issue in Science and several of the results are very surprising, including that she had arboreal adaptations (i.e. traits for living in trees) despite being bipedal.
Anyway, I don't have much to say (not my field) but I do want to point to this video (embedded below, or click here) that the team at Science produced and that has not received enough playtime. It's a great primer on the significance of the find and what it could tell us about hominid evolution.
(By the way: John Hawks has pointed out that one of the photos used in this video is poorly scaled, so it doesn't give a good indication of the skeletal proportions).