In a previous post back in June '08 discussing the unhappy history of nuclear-powered aeroplane designs from the 1950's to the 1970's, I ended by wondered whether anyone was still thinking big.
Seems like some people are trying to give atomic airplanes a second chance. SciAm has an online article by Karen Frenkel discussing this, although tellingly she notes that nuclear physicists and nuclear engineers are generally NOT in favor of it.
If it'll have more leg-room per seat I'm all for it! (Just kidding, the problems raised in the article do seem quite serious.)
[Image from wikipedia of the Convair NB-36H nuclear reactor testbed.]