Meet the Gyro-Fit: a portable exercise system that lets you perform cardio anywhere. It serves as a jump rope and no line jump hula hoop. Its retractable rope can be adjusted to your height. To use the Hula hoop, simply put Gyro-Fit around your waist and move your hips.
You can also use the Gyro-Fit to engage more muscles while walking or running. More info is available here.