That was the question asked by CNN (What?  Has it been a slow news week or something, guys?).

Okay, an intriguing question, I suppose.  Let’s see.  What could the answer be?  A small copy of the Constitution?  A bible verse?  A letter from a U.S. soldier stationed in Iraq?   A picture of his family, or Barney?

Any of these things I would find suitable for Dubya to carry around in his pockets (since he is, you know, Dubya).

I’ll remove the suspense:

When the reporter from La Nacion asked Bush to show him what he carries, the president stood up, fished in his pockets, then dramatically pulled his hands out holding nothing but a white handkerchief that he waved playfully in the air.

"Es todo," Bush told the Spanish-speaking reporter, meaning the handkerchief was all. "No dinero, no mas. No wallet."

Come to think of it, THAT is an appropriate answer as well — nothing but the waiving of a white handkerchief.