I studied a lot about magic routines and can tell you for many big magic tricks on youtube at least one possible way how it would work. But the most important thing about magic is, it is entertainment. And also Derren Brown is an entertainer, that's what he does. I'm a big fan of Derren, also because he exposes much of the supposedly psychic or prayer stuff.

I clearly agree with garethrees' point about misdirection and psychology. Providing a solution that seems plausible to system 1 (sensu Kahneman), makes you stop thinking about it. I think that one of Derren's best tricks is to make the audience feel happy with a fake explanation. In general, I don't like exposing magic tricks. But in some cases when false beliefs spread by magicians clearly threaten to poison people's belief systems, I make sort of an exception:

• The old magician's rule "80% show, 20% magic skills" is still true and also applies to Derren
• Derren is an excellent sleight-of-hand magician. Many tricks that he presents as mental tricks, are card tricks (for example http://www.youtube.com/watch?v=AewhMHhCmNQ)
• Forget suggestion and NLP in the way Derren uses them as explanations. All his tricks are clearly possible without them.
• Often, solutions of "impossible" tricks are very disappointing in the sense that one realises that the actual trick was to make one believe that the magician would not use "cheap" tricks (for example see http://www.youtube.com/watch?v=EUiToBs_YT0), or that the magician would not be able to see through a blindfold, or…
• On TV, you can easily select for what you want (nicely demonstrated by Derren's "The System", http://www.youtube.com/watch?v=9R5OWh7luL4)