I poked around StackOverflow and Google, but couldn\'t find anyone who has put together a comparison of authentication gems or plugins for Rails (I\'m looking for something
For a Rails3 App definitely Devise ;). Devise is the only authentication system which provides security on all the 3 stack layers of rails: - In 'M', 'v', and 'C' and hence the best to go with. But you got to learn more on how to customize devise to custom fit your application's need. You can find help on customizing in this page https://github.com/plataformatec/devise/wiki/_pages
devise, devise, devise