I've noticed these signs as I drove past, but I've never stopped to collect them, yesterday I did. These signs attract me because of the humanness of them and the lack of consciousness when creating them. I also found and read Typography for the People which suggested that to a trained designer signage like this might be a point of jealousy. They aren't playing by the rules, they are just making, playing, and doing. Creating without the ever-present self-conscious critic would be a delight.
See the whole set on flickr here. Taken with Hipstamatic.