David Rothenberg does two way underwater communication experiments with Belugas in the wild. One of the most advanced communication research in the world today, at least in the non-military field.
David has written a book on his work, to be published later in 2008: Thousand mile song
"Whale song is an astonishing world of sound whose existence no one suspected before the 1960s. Its discovery has forced us to confront the possibility of an alien intelligence not in outer space but right here on earth. This title uses the enigma of whale sounds to open up whales' underwater world of sonic mystery."