Installing Ruby 1.9.2 and Rails 3 stable on Ubuntu

There are a zillion threads on internet regarding fresh installation of ruby 1.9.2 and rails 3 on ubuntu, however, most of them have some sort of dependency missing. Lately, i found a very helpful link on this topic, so i thought of sharing the post

http://torqueo.net/installing-ruby-192-and-rails-3-stable-on-ubuntu/