Using symbols for controllers and actions

Hello

I am a newbe to rails. One of the things that confuses me is the usage of symbols and strings to refer to actions and controllers. Which of the following would be the right way to go:

<%= link_to 'Login', :controller => 'user', :action=> 'login' %> <%= link_to 'Login', :controller => 'user', :action=> :login %> <%= link_to 'Login', :controller => :user, :action=> :login %>

Or is it just personal taste? The last one probably spoils things like:

<%= link_to 'Login', :controller => 'advanced/user', :action=> :login %>

Any enlightments appreciated.

best regards badbrush