Wow, this is a really old thread! It's been silent since before I ever came here (which is probably why I've never seen it).

Just for interest, speaking in tongues (glossolalia) is also very useful for inducing a trance state, much like a mantra. The Apostle Paul was certainly a big fan of it, and he was a pretty metaphysical guy (he also had out of body experiences, amongst other interesting things).