It can sound like stupid, but i've heard that in europe people can to
float, and in the USA there are 100, 000 persons that float.

So please answer that: 
How can I use my mind to float, to have supernatural powers???

Don't believe everything you hear. I have seen video of people who
claimed to be levitating. They were not doing anything supernatural.
They were essentially just hopping into the air. Perhaps they had the
mental sensation of floating, but it was entirely subjective.

Check out this thread:
http://answers.google.com/answers/threadview?id=553439

And as to those people sitting in the lotus position with their legs
crossed, they can't do it either.
Europeans  - and I am surrounded by them -  have no supernatural
powers, at least as far as levitation is concerned.  There are some
researchers here  - as in the States (Hi ^!) who seem to have at least
very uncanny powers.

These people are the ones on earth closest to understanding how humans
might eventually be able to defy gravitational forces.

http://www.ligo.caltech.edu/

:)

Enjoy!