I have a slack-line but get very little opportunity to use it. I'll start keeping it in the vehicle so I can bring it on kayak expeditions–adequate clothes-line and camp couch–and on the off chance I find a spot to use it.

I am looking to increase the impact, not reduce it. I know that I need more bone-rattling in my life and can't justify the purchase of a Juvent. Skateboarding provides benefits similar to that of a Juvent, plus I might learn how to fall (and skate).