I actually took some time off the other week, and besides attending NADWCon I spent a bit of time at the National Aquarium while hanging out in Baltimore. One of the more interesting exhibits was the Jellyfish section, which had quite a selection of types. As I remembered from swimming in the ocean, Jellyfish are not real good at orienting to the local up and down, which should be a bit of a plus for surviving in space (or any other zero G environment).
