Brad Pitt greeted fans in Madrid, Spain, on Friday in the middle of his whirlwind promotional tour for World War Z. Earlier that day, Brad toured Moscow with his children Shiloh and Zahara after walking the red carpet for his project's Russian premiere on Thursday. He has been traveling the globe to do press for the flick, and has already made stops in London, Berlin, South Korea, and various cities in the States. Brad's grueling schedule hasn't been for naught as his film pulled in $66 million this weekend, marking Brad's biggest box office opening weekend ever. Prior to World War Z, Brad's biggest debut weekend earner had been 2005's Mr. & Mrs. Smith. Now there are rumors that Paramount, the studio that produced the film, and Brad are eyeing the possibility of a World War Z sequel. The project was initially created to run as a trilogy, but those plans were shelved when the film ran into production trouble last year.