Failing "foo_bar".titleize outside of Rails

I'm pretty sure that this sort of thing is meant to work now in Rails3

require 'rubygems'
require 'active_support/core_ext/string/inflections'
"foo_bar".titleize

It doesn't, failing dependency on 'active_support/inflector' - here's a ticket with (very simple) patch:

https://rails.lighthouseapp.com/projects/8994-ruby-on-rails/tickets/4067