Interesting idea. What I don't get about most of these theories, though, is how they can explain others not getting affected by whatever. Theoretically, people are close enough to the Pythia that the interpreting priests or the visitors or whoever's around would be affected too.
Hell, maybe the Pythia was just really damn good at making herself go into a trance (some sort of meditation?) or even just acting (but, y'know, god-inspired acting).
Also, does anyone know what's up with most of Perseus' sites being down? I was only able to access the German mirror site for any length of time tonight! And that was pretty slow! Or maybe I should have kept my "secret" about use of the German mirror site, lest the traffic grow worse. ;-)
Edited to add: Perseus seems to be working well this morning, so I guess it was a temporary fluke. I worry about the well-being of Perseus too much!