Tag for creating ajax callback links

<%= link_to_remote( "click here",
                         :update => "specific_div_block",
                         :url =>{ :action => :action_name }) %>

Basic rails link tag

<%= link_to 'Link Name', { :action => 'action_name', :id => 0 }, :confirm => 'Are you sure?', :post => true %>

// esta es una forma muy buena de hacer un pop up desde un link

<a href="http://google.com/" onclick="window.open(this.href, 'popupwindow', 
  'width=400,height=300,scrollbars,resizable'); 
  return false;"
>