As I think about and show the Dictionary of Words in the Wild 
I’ve come across some neat web sites that deal with public textuality in different ways. illegalsigns.ca is dedicated to tracking public advertising and the law in Toronto.
Melissa sent me a link to a great mashup, The London Evening Standard Headline Generator from thesurrealist.co.uk. She also pointed me to a Flickr collection Evening Standard Headline Crisis 2007 which collects images of the headlines displayed on the boards. Looks like the raw material for the Generator.