I recently saw an episode of "Bill Nye the Science Guy" on PBS (see
http://nyelabs.kcts.org) that was about marine mammals. One interesting
shot showed trainers/vets taking milk from a dolphin using what looked
like a human breast pump! The dolphin was on its side at the surface of
the tank.
I wrote the show's researchers asking for more info. I'll send it along
if/when they reply.
--Kelly