This is way too cool. Many people know that toothed cetaceans (like dolphins, sperm whales, killer whales, etc.) use echolocation as a sensory tool to find their way around and to hunt for food.
Researchers have traditionally viewed baleen whales (like humpbacks) as being unable to do this. Until now.
A research team (comprising members from the Hawaii Institute of Marine Biology, Woods Hole Oceanographic Institution, University of New Hampshire, NOAA's National Marine Sanctuary Program) has documented humpback whales making clicking sounds, quite possibly in pursuit of prey.
A recent press release from NOAA on this exciting discovery is here. And here's a recording of the humpbacks (Source).
[mp3]http://www.tonywublog.com/audio/2007/megapclicks.mp3[/mp3]
This is beyond cool in so many ways, but what excites me is the fact that this is a discovery that flies right in the face of established "knowledge". I get so fed up with people whose minds are closed to new possibilities that I absolutely love developments like this that turn fact into fiction.