Meet the Zoa PL1: a portable rope tow that you can use for skiing and snowboarding. You simply have to tie a line to a tree, drop the line along, attach it to the PL1, and you are set. You can use this device to propel yourself up the mountain without breaking a sweat.
The PL1 weighs 10.5lbs. It has max tension of 180 lbs. You can find out more about it here.