We like where entry #45 is headed, but were wondering if you could try it without the gradients (just flat colors and shadow shapes where necessary). Again, similar to the plancast penguin (
http://plancast.com), android logo, and another one I recently came across was the hipmunk logo (
http://hipmunk.com). Possibly play around with the facial expression and features, and maybe the shape and placement of the arms and legs.
Also, take a look at the update we just made to the brief. One of our founders created a character that we like a lot and want our designers to work with. Given your entries, we would be curious to see what you could come up with.