Heavily-based on Keyvan Akbary's PHP slugifier.
We use this at Chicisimo.
Some systems define a slug as the part of a URL which identifies a page using human-readable keywords.
http://en.wikipedia.org/wiki/Semantic_URL#Slug
require "slugifier"
Slugifier.slugify("Here's to the crazy ones") # => here-s-to-the-crazy-ones