Visual object-relational mappers allow you to integrate different DB schema and classes/objects, instead of deriving one from the other. What do people think of them? They aren't appealing to me, because they aren't very code-like... however, some relationships between disparate type-systems are much easier to express graphically than in code.

URL parameters: http://rails.nuvvo.com/lesson/6371-action-controller-paramet...

I really prefer Sinatra's way of doing this; and it's probably even more appropriate for prototyping (but not for big projects, where separate directories help handle complexity.) It's just amazingly simple and intuitive: http://www.sinatrarb.com/intro.html

      get '/hello/:name' do
        # matches "GET /hello/foo" and "GET /hello/bar"
        # params[:name] is 'foo' or 'bar'
        "Hello #{params[:name]}!"
      end