It would never happen, because then places would lose out on their small tourist appeal, but I have always wished that there was a place that housed a lot of "oddities" from around the country. To include: The biggest ball of yarn in Cawker City, Kansas; The tallest totem pole in Foyil Oklahoma, The blue whale of Catoosa, OK; The foamhendge in Natural Bridge, VA; The world's largest ball of paint from Alexandria, Indiana; Salem Sue from New Salem, North Dakota; etc.
I think if all placed together, and charged an entrance fee, then they might be able to make money if the park was large enough. That way all of the crazy and random attractions would be in one spot. But kind of like the road sign idea, a lot of the fun and importance of it is that you actually traveled and were there