I found an interesting podcast on iTunes by the Center for Global Apologetics of Liberty Seminary. The president of the seminary, Ergun Caner, interviews representatives of various cults such as Jehovah’s Witnesses, Mormons, and Baha’I. There's also an interview with Dr. Mel White, dean of the Metropolitan Community Church.
Each podcast is not a debate, but a well-done and respectful interview full of really practical questions. (Like to the two Mormon elders, Caner asks, "Why the bikes?!") The interviews are apparently seminary classes, and after Caner's interview there are questions from the students.
If you want to learn what some of the cults believe and teach, check this out. It's called "Sects and Cults Podcast" in the iTunes store, and it's free.