I love the idea! Akin to that, I envision myself guest hosting for free lodging at National Parks. We are avid Park campers and I think it would be a good fit. At first I want to enjoy my freedom, but after we settle down to retirement life, picking up some guest hosting or cool jobs activities will be a fun diversion.
Also, at National Parks there are alot of folks who are hired on seasonally. Think Yellowstone National park size locations where there is a community with cabins for the workers to live in. That will not fit my retirement lifestyle (I know I will be an RVer) . I enjoy reading peoples badges which typically also show where they are from.