I like the jumping cue, but different cues for different people. The hips are a core part of jumping. Besides, Dastardly's point was more that it's the legs and hips, not the arm muscles, that lift the weight on a clean, i.e. think of your arms as ropes, and "arms bend, power ends."
Video of Ripp coaching the power clean in terms of the jumping position:
http://media.crossfit.com/cf-video/C...rCleanJump.wmv
I'm too new to this forum to know whether this is common knowledge, but there are videos on training several lifts at the Crossfit site. Search the page for "Rippetoe" or "Burgener" or the name of the lift.
http://www.crossfit.com/cf-info/excercise.html