This was the first workout in the first CrossFit open in 2011. Check out the demo video 30 Double Unders and 15 Power Snatches. There is a great example of the workout with Laura Glassie.
Mobility/Skill WOD
Max Toes to Bar in 30 Seconds x5
Keg Drill 1 Min x4
WOD
30 Double Unders
15 Power Snatches (75#/55#)
10 Min AMRAP
Pat and Nick on the sit ups, Taylor and Ali on the swings! 6:30 crew going for it!