The plugin restful_authentication and other plugins that extend it, answer your needs perfectly. A quick search on github.com will reveal a lot of tutorials, examples, and extensitons. Just go here:
- http://github.com/search?q=restful_authentication
There are several projects that use restful_authentication just to provide examples of a bare-bones Rails app with just the authentication parts.
- http://github.com/fudgestudios/bort -- A base rails app featuring: RESTful Authentication
- http://github.com/mrflip/restful_authentication_example -- Another project with a great examlpe of how to use restful_authentication
- http://github.com/activefx/restful_authentication_tutorial -- Same as above, with some other plugins bundled.
- http://railscasts.com/episodes/67-restful-authentication -- a great screencast explaining restful_authentication
This information should be enough to get you started finding heads and tails ... good luck.