A pair of US astrobiologists have come up with a cunningly simply way of attracting the attention of alien lifeforms - just cover half the Moon's surface with mirrors to throw back some extra sunlight in ET's direction.
According to New Scientist, Shawn Domagal-Goldman and Jacob Haqq-Misra of Pennsylvania State University in State College reckon the Moon-mirror could act as a kind of heliograph to beam a "code of prime number flashes" - just so distant beings fully get the message.
More: http://www.theregister.co.uk/2008/04/29/moon_mirror_plan/
(Isn't it a bit late for April Fools? ;) )