[Rails] Rewrite domain root to MainController#index

["Luis G. Gómez"]

Is there a way of preventing rewrite rules from rewriting
requests to domain root (http://www.example.com/) to "/controller/action"?

I want to hace a "main_controller.rb" hadle, among other actions, 
"index" without showing the user "http://www.example.com/main/index" but 
simply "http://www.example.com/".

I tried adding the following after lines 23, 33 and 39 respectively:

	RewriteRule ^fcgi/$ /dispatch.fcgi?controller=main&action=index [QSA] [L]
	RewriteRule ^mruby/$ /dispatch.rb?controller=main&action=index [QSA] [L]
	RewriteRule ^$ / [R]

...bu nothing.

Actually I get

	"Redirection limit for this url exceeded.
	Unable to load the requested page.
	This may be caused by cookies that are blocked."

I understand the message and why it happens but don't know how to get 
what I want.

Has anyone tried tried doing this?