How to add extension to routes?

Hi,

I noticed that all routes have an alternative format ending in .:format. I
tried this out, adding .html to some routes, and it worked.

But I wondered how you can add an extension like this automatically to
generated paths? For instance if I have a model named Book, and so a route
named books_path, how can I get: /books.html?

Thanks,
Brandon

formatted_books_path(:format => "whatever_format_you_like")

you can also go rake routes to see a list of all available routes and
formats.