Sheep World is unironically rad. I thought it'd be very weird and/or boring but we had a blast I'm not sure on the legalities of putting signs up. I wonder if you can just put anything up anywhere (within reason) or if you need some kind of approval from the Transport Dept or something similar? Regardless, it's a great idea to get one up if you can. I bet you five dollars you'll be more busy again in the next two weeks once people get out of holiday mode.