Okay, I just saw this for a ropeless jump rope. And it will even make the swish sound for you as if you had a real rope. This is why marketing people get paid more than we do:
I believe this is on the same level as that garden hose exercise thing David Carradine was pushing:
Interesting … none of the models in the video are actually jumping, as in, getting their feet off of the ground. They’ve probably already sold out the first two production runs. BounceSnap might be a better name.