Glimpse of a new type of matter: Frozen helium has been turned into a solid that behaves like a superfluid.: "Researchers in the United States think they have found a new state of matter - a supersolid.
If their findings are correct, this state is deeply bizarre. Although it is a crystalline solid, it can 'flow' like the most slippery liquid imaginable - in fact, like a liquid with no viscosity."
Been wanting to post this for a week, wanted to read about it, but haven't had a chance to follow up yet.