Make nginx with ruby on rails have case insensitive URLs

Question

We are using nginx + passenger and Ruby on Rails. We would like all URLs, not just controllers and actions to be cases insensitive. This works fine by default on the Mac I'm developing on but when we moved to linux with its case sensitive file system, we have a bunch of broken images. I'd also just like URLs in general to be case insensitve for people trying to remember them.

I tried this: http://gehling.dk/2010/02/how-to-make-rails-routing-case-insensitive/

but could only get it working for Rails actions, not static images and such.

thanks for any help.