That sounds like a blast! My best friend rides in the Prouty each year, in association with the Dartmouth Hitchcock Medical Center Cancer nurses. That's also a summer ride, lasting a couple of days but always focused around Lebanon, NH. One of the things they do is have people who will dump water over you. Or hand you a cup that you can dump over yourself. I think having the route of the RAGBRAI change each year to visit different towns is a cool idea.