"Alone among snakes, anacondas are unique. After eating their prey, they regurgitate in order to eat again."This information is included in the opening titles of "Anaconda,'' and as the words rolled across the screen I heard a chuckle in the theater. It came from me. I sensed with a deep certainty that before the movie was over, I would see an anaconda regurgitate its prey. Human prey, preferably.