Fed up of empty wrapper html tags when content isn't there? Then use this Rails helper...

  def tag_unless_empty(html_tag, options = {}, &block)
    html_options = options.stringify_keys

    if block_given?
      content = capture(&block)
      unless content.strip.empty?
        concat(tag(html_tag, html_options, true), block.binding)
        concat(content, block.binding)
        concat("#{html_tag}>", block.binding)
      end
    end
  end

Example:

<% tag_unless_empty :div, :class => "css_class" do %>
   <%# Nothing actually rendered here %>
   <%# or here %>
<% end %>

produces nothing, whereas

<% tag_unless_empty :div, :class => "css_class" do %>
   <%= 'Something rendered here' %>
<% end %>

produces

<div class="css_class">Something rendered herediv>