In the following video he unmask the once famous israeli psychic Uri Geller and the christian healer Popoff (and yes,that's Ricardo Montalbán at Geller's right).
And here The Amazing Randi doing his thing again (at this time he only offered 10,000 dollars)
I hate those damned healers (really sinister guys ,if you ask me) playing and getting money with the hopes of faithfull people be careful because Randi is around!
And finally about horoscopes
I strongly recomend you these two James Randi books (I read them more then once and check them now and then) they are not just a good lecture but a couple of eye openers in case one is in need of that, or just in doubt. Funny how Asimov and Arthur C. Clarke (each one introduce one book), two very rational fellows and probably the most famous science fiction writters have Randi in very good opinion and thank him for his work (in case my word is not good enough).