A long time ago I solved a nagging issue concerning Rails’ handling of url casing (or rather: non-handling). I posted the resulting code here.
I’ve realised that a lot of people are actually using this solution, so I finally took the time to make it into a fully-tested gem.
The gem is released on RubyGems here.
All documentation (such as is needed) can be found on the gem’s github page.
All you actually need to do is adding the gem to your gemfile, run bundle, and the gem takes care of the rest. No config or initialization code needed, it’s all baked into the gem.