that's a great idea, it's loveable, recognizable and easy to use cross-medial since it's flat and almost unicolored. i think BSH's aliens are lovely too, but they might prove to be harder to implement in different forms/functions. edit: the bloodcells idea is pretty nice, but i don't think it can compete with (for instance) azureus' "living" logo. somehow an abstract concept seems to focus a little too much on the technical side of the program, rather than it's usability (which is, in the end, more important to give µtorrent true mass appeal).