You're right that I completely missed the Bayesian boat, and I'm going to have to start thinking more before I speak and revise my estimates down to <1%.

But I'm still reluctant to put them as low as you seem to. The anthropic principle combined with large universe says that whatever complexity is necessary for the existence of conscious observers, we can expect to find at least that level of complexity. Questions like consciousness, qualia, and personal identity still haven't been resolved, and although past experience suggests there is probably a rational explanation to this question, it isn't nearly dissolved yet. If consciousness really is impossible without some exotic consciousness-related physics (Penrosean or otherwise), then our universe will have exotic consciousness-related physics no matter how complex they need to be. And since evolved beings have been so proficient at making use of normal physics to gain sensory information, it's a good bet they'd do the same with exotic consciousness-related physics too if they had them...

...is a somewhat hokey argument I just invented on the spot, and I'm sorry for it. But the ease with which I can put something like that together is itself evidence that there are enough possible sides of the issue that hadn't been considered (at least I hadn't considered that one; maybe you've been thinking about it for years) that it needs at least a little more room for error than two in a bajillion (sorry, Alex).

I also disagree with your assessment of the amount of evidence. Have you ever read any good books by intelligent believers in the subject? It's not all John Edwards psychic chat shows. I also think you might be double-counting evidence against psi here - psi doesn't exist so we know any apparent evidence must come from human psychology, therefore there never was any apparent evidence in the first place. Or have you read the studies and developed separate explanations for each positive result?

Anyway, let's settle this the LW way. Give me your odds that psi exists, and we can make a bet at them. If it's one in a million, then I'll give a cent to your favorite charity on the condition that you give $10,000 to my favorite charity if psi's shown to exist within our lifetimes (defined however you want; possibly as evidence sufficient to convince any two among Randi, Dawkins, and Eliezer that psi is >50% likely).