I'm doing an article on functional typography, but not ordinary type. Forget legibility etc. What I want to dicuss is type that has another function besides the presentation of letters and words. Think: Manhole covers, the type gives the name of the manufacturer and perhaps the city, but it must also create grip for the soles of shoes. Braille (probably spelt wrong) must be legible to the hand not the eye.
What I need help with is coming up with more examples...so post away.
Thanks.
P.S. I found this site the otherday, its amazing!