FWIW, I would recommend using the gems instead of the plugins. You can put the configs in your config/environments/test.rb as such:
config.gem 'rspec', :version => ">=1.2.6" , :lib => false
config.gem 'rspec-rails', :version => '>=1.2.6', :lib => false
config.gem 'webrat', :version => '>=0.4.4', :lib => false
config.gem 'faker', :version => '>=0.3.1', :lib => 'faker'
config.gem 'notahat-machinist', :version => '>=0.3.1', :lib => 'machinist', :source =>'http://gems.github.com'
The nice thing about gems is that you can include them on a per-environment basis. Plugins load by default in all environments.
I also use webrat, faker, and machinist ... you may want to check these out.
Once you've updated your config file, just:
rake gems RAILS_ENV=test
and you will see that some of the gems are not installed. To install them, either do it manually, or let Rails help out:
rake gems:install RAILS_ENV=test
Finally, when you want to generate a controller and spec, just:
ruby script/generate rspec_controller some_controller_name
and when you want a model and spec:
ruby script/generate rspec_model some_model_name
These aren't scaffolding generators; they just create the empty spec files and they don't clutter up your test directory with tests you won't use because you're writing specs instead.