It's similar to another clip from the same show, which was also declared the "best" caller. The clip was basically someone calling in and claiming proof of God's existence was, basically, because stuff exists and came from somewhere.
+5 for the 'Thomas Aquinas he is not' tag. I hope there are some more videos with that wonderful distinction.
Hopefully some day someone (a non-idiot) will call this show asking them about Anselm's ontological argument of God's existence. It's pretty interesting: http://www.princeton.edu/~grosen/puc/phi203/ontological.html
i almost pissed myself when i heard that one in philosophy class in high-school. anyway they mentioned it in one of the podcasts ,i think, to much work to go fish it out, the archive is huge.
The best (and easiest) way to collapse Anslem's argument is this: 'All of what you claim to be proof of the existence of God is held in the eyes of an infant viewing it's mother'. To that infant, there is no greater being in the universe, however while in the mindset of the infant the mother is God, the truth is that the concept of perfection and universality are merely human traits of subjective experience, and thus not axiomatic proofs.