Using the new cookie-based sessions

Hi all,

I'm just about to deploy my first big site, and i want to use the new
cookie-based sessions, instead of pstore or mysql sessions, as i've
read about here: http://dev.rubyonrails.org/changeset/6184

Any tips how i'd do this? What files do i need to copy into my rails
app directory?

Thanks a million guys

More details are here:

http://ryandaigle.com/articles/2007/2/21/what-s-new-in-edge-rails-cookie-based-sessions