Rails / Ruby DateTime Stuff

A great blog entry: http://anandmuranal.wordpress.com/2007/12/12/formating-date-time-in-rails/

Rails update a gem to an older version

You want say rack version 1.0.1 but the latest version is rack 1.1 and it's installed on your machine:

gem install [gem name] --version [version number]

For example:
gem install rack --version 1.0.1