using AR outside of rails

I've seen a number of ways to use AR outside of rails, and am wondering what other think is the best approach for my particular application.

The application is in it's own module namespace. To use it within rails you just require it in application.rb and instantiate a class to call methods on. It's also well suited to be used from other various applications though. The simplest way I could think of to make my application work inside and outside of rails without much user intervention would be something like this.

require 'activerecord' if ENV and ENV.has_key?('RAILS_ENV')   require 'models/mymodel'   ActiveRecord::Base.establish_connection() end

I'd probably use a yaml file to store the database configuration like rails does.

Any better ideas?

Argh that should have been: unless ENV and ENV.has_key?('RAILS_ENV')