Authentication in Rails 2

Update: Seems like Devise is more popular and is better supported. It works great with Rails 2 and rails 3

After trying several Ruby on Rails authentication solutions I think that Authlogic is the best one. Authlogic can be installed as gem and as a plugin, does not require the use of generators (only optional scaffolding to save you time) and is very modular.

A very well written tutorial is here. The github repository is here