If the effect is in print as someone suggests then I wouldn't want to say too much incase I happen to be right in my supposition of how the pull effect is achieved...but this was just an observation I've made (and I'm sure so have others!) from everyday life:
It's really quite hard for you to stand still on a spot for a few minutes without adjusting (I'm sure thats spelled incorrectly!!) your balance!

I thought about it for a while and realised that the person was always going to fall and Derren Brown enforced that with his own techniques and made it appear as if a miracle had happened... I think alot of the work he does is about making it appear as though he made more happen than he actually has... but then, that kind of applies to magic in general and is part of what makes it so good to watch!
Corindas "13 steps to mentalism" is a great resource for mentalism in general though I'm sure with practice, thought and the right presentation that it's possible to pull off many magical effects as though they are mediumisticalorific. Also, I'm sure there are books available on cold reading in particular if thats more your bag (just be aware of books meant for actors auditioning... I read that warning on a review on amazon!).
Hope this helps!
