According to a study published in the October issue of Current Biology entitled "Spontaneous human speech mimicry by a cetacean," whales can talk.
Not to burst your bubble ring or anything, but now that we've suckered you in, let's clarify what we mean by "talk."
A beluga whale named "NOC" (he was named for an incredibly annoying sort of Canadian gnat), that lived at the National Marine Mammal Foundation (NMMF) in San Diego up until his death five years ago, had been heard making some weird kinds of vocalizations. At first, nobody was sure that it was him: divers heard what sounded like "two people were conversing in the distance just out of range for our understanding." But then one day, a diver in NOC's tank left the water after clearly hearing someone tell him to get out. It wasn't someone, though: it was somewhale, and that somewhale was NOC.
Once NOC had been identified as the source of the vocalizations, his trainers started to pay more attention. The sounds that NOC was making were entirely unlike normal whale sounds: they were much lower in pitch, and had a bursty rhythm that was very similar to human speech patterns. Furthermore, NOC never made the sounds when communicating with other whales: he just made them while alone, or when humans were around.
Here's what NOC sounded like:
While not exactly speech as we'd think of it, most cetacean researchers seem convinced that, at the very least, NOC was deliberately trying to mimic the sounds he heard from humans, and doing rather a good job of it, all things considered.
However, according to one researcher, as quoted by Discover's Ed Yong:
"I don't think the whale was trying to learn human speech in order to communicate with humans." Instead, he suggests that NOC was simply interested in these odd sounds in his environment, and tried to reproduce them.
Might we suggest that NOC actually was trying to communicate with humans. Maybe NOC was getting fed up with attempting to punch footballs or whistling for tidbits. Maybe, after unsuccessfully trying to send one final message through what we humans misinterpreted as a surprisingly sophisticated try at doing a double backflip through a hoop while whistling "The Star-Spangled Banner," NOC tried to learn human speech to communicate this: so long, and thanks for all the fish.