Photos: The puzzling life of Rubik's cubers

The 2009 Rubik's Cube U.S. Nationals, which took place Friday through Sunday at Stanford University in Palo Alto, Calif., is one of the best known annual Rubik's Cube events in the U.S. Launched in 2004, it draws competing puzzlers from more than a dozen countries.

The competition involves 18 events that test skills like puzzle solving speed, fewest moves, and even ability to solve the puzzle blindfolded from memory. There are also competitions for other puzzles, like Rubik's Magic, Megamix, Pyraminx, and the Rubik's Clock.

Here, Jameson O'Connor, of the U.S., collects his thoughts before competing in the 3x3x3 Blindfold qualification round, in which he scored a personal best time of 7.23 seconds. In the event, a Rubik's Cube with 3 bricks on each side must be completed blindfolded. Players have to use memory tricks to recall the correct positioning and moves necessary to complete the puzzle.

David Calvo, competing in a blindfolded competition, traveled from Spain to compete in the Rubik's Cube U.S. Nationals.

The TouchCube is a new game from Rubik's Cube. An electronic version of the classic puzzle, the colors are moved and arranged by touch.

After a successful qualifying round in the 5x5x5 Blindfold competition, a judge certifies the results.

To compete in the blindfold competitions, players use a variety of techniques, ranging from memory recall tricks to math, to successfully complete the puzzles.

Competitors exchange notes and techniques with each other as they practice prior to the qualifying round on Friday in the Dinkelspiel Auditorium at Stanford University.

Weston Mizumoto, of the U.S., takes one last look at his cube before the competition begins. After six tries in Round 1, his average time in the 3x3x3 Speedsolve was 18.59 seconds, placing him 58th.

With puzzlers intensely focused, the auditorium was silent except for the clicking sounds of the rapidly spinning cubes.

The strongest competitors in the Rubik's Cube puzzle competitions are typically the 14- to 16-year-olds, according to U.S. Nationals organizer Tyson Mao. He estimates that with about 200 hours of practice, a Rubik's Cube enthusiast can become competitive in national competitions.