Sure, if you pick up almost any book on Tarot, it's going to have some mystical nonsense in it, but it's also a tool for brainstorming and an inexpensive way to get a lot of cool art. Check out The Sceptic's Tarot if you're curious about non-supernatural usage of Tarot cards.

Also, some people have found it to be an aid for psychology, similar to Rorschach tests. I don't think this has been studied, though.