Plugins - FixtureScenarios
Add to favoritesThis plugin allows you to create "scenarios" which are collections of fixtures
and ruby files that represent a context against which you can run tests.
http://code.google.com/p/fixture-scenarios/
http://fixture-scenarios.googlecode.com/svn/trunk/fixture_scenarios
Rails' (MIT)
Testing

I use this plugin daily and it's terrific. It should be part of Rails core IMHO.