Dolphin joke...made it up myself today. :)

An aquarium guide brought a group of visitors around to see the dolphins, which were split up into two tanks. In the first tank the dolphins were all having fun, playing around with a beach ball. In the second tank the dolphins were training, working hard on a new trick. One of the visitors asked the guide, "So is this tank for the more serious dolphins?" The guide said, "Yes, for all intensive porpoises."