Physicists Successfully Store and Retrieve Nothing

I have to look up a copy of the actual article from Phys Rev Lett, but this is incredibly cool: Physicists Successfully Store and Retrieve Nothing

Basially, it seems to me the researchers managed to create a stationary excited vaccum state. The article describes it about as well as I can (especially since I haven't read the paper yet, and my quantum electrodynamics kung-fu isn't all that strong), so you should probably read that, but... Wow.