This jQuery plugin sets the height on iframes based on their content. http://github.com/house9/jquery-iframe-auto-height
<%= yield %>More: <%= link_to "Main", :controller => "containers", :action => "index" %> | <%= link_to "Another Pic", :controller => "containers", :action => "index2" %> | <%= link_to "Dynamic", :controller => "containers", :action => "index3" %> | <%= link_to "Min-Height", :controller => "containers", :action => "index4" %> | <%= link_to "Callback", :controller => "containers", :action => "index5" %> | <%= link_to "Form", :controller => "containers", :action => "index6" %>
Original code by Nathan Smith, see original article.