Toads like to dig. So I'd sit it up with a couple of inches of dirt. I think it's easiest to have a water dish, that way it can be easily removed and the water replaced without much trouble. As someone else said, toads are tough and adaptable. I've found their main interests are digging and food.

Tim

Red-spotted Toad that I found near Vegas last month:
http://www.thirdeyeherp.com/
http://www.thirdeyeherp.com/