traveling with turtles

This may be an odd quesion…but has anyone flown with a turtle? It is possible that I will be visiting somewhere near a reptile exposition, and could purchase a turtle there. (since there are rarely, if ever, any within easy driving distance of where I am….at least, to my knowledge.) But, of course…I would then have to fly home with the turtle. Are there rules/regulations about transporting live animals in your carry on luggage? Are you supposed to have any sort of “OK” from a vet, or any other authority…so they know that you are not transporting a diseased or illegal animal? Or can I just put the little fellow in a container, and put him in my carry-on bag? (I just can’t help wondering what they will say if I am picked for a random bag search…and they find a baby turtle! And, more importantly, whether or not they would confiscate it!) -Abby : )