If you're still afraid that the Wii might send you to the emergency room, perhaps the "JumpSnap" is right for you. At least there's no rope to strangle yourself with.
That's right, this is jump sans rope. The JumpSnap is basically a set of two electronic handles that are programmed to lead you through workouts, with sensors to gauge how well you're doing along the way. However, as SCI FI Tech points out, the coordination aspects of analog rope-jumping seem to get lost in the translation to the virtual version.
A kids-size alternative could be the "Electronic Jump Rope Jam," but we'd probably still manage to hurt ourselves.