They say that you shouldn’t ever use non-rated gear for climbing, and “they” are definitely right. But rated climbing gear is also super great for a lot of other purposes!
You might have a Purcell Prusik, or you might have never heard of one. But it’s a pretty cheap way to anchor yourself (relatively redundantly) onto a wall. I wont get into it because there’s plenty of guides online on how to make a purcell prusik. But it can also be used as a carry strap for carrying a longboard! The adjustable arms can be shortened or lengthened to fit onto a variety of longboards, and cinched down tight so your board doesn’t swing once its on your back.
The adjustable length allows it to be used for both short and long longboards! I like to use a carabiner with a wide gate so it’s easy to carry the sling on your belt loop when riding, and you can use it to clip onto the trucks.
Additional uses include a pull cord for hitching on your friends bikes, and for dragging your board up a steep hill!