I'm sure someone has already done this but I didn't find it in list-abstractions or anywhere else so I figured I'd post my own solution.
In messing with list I've found that sometimes in a patch I'll have to keep several instances of the same list. I figure this called for a [value] for lists, so I created [list-value] which works just like [value] but stores and outputs lists instead of floats.
I've attached the abstraction and a help file in case anyone else would like to use it.
-Alex