module ActionView::Helpers::CacheHelper

def cache_unless(condition, name = {}, options = {}, &block)

<% end %>
<%= render project.topics %>
All the topics on this project
<% cache_unless admin?, project do %>

Cache fragments of a view unless +condition+ is true 
def cache_unless(condition, name = {}, options = {}, &block)
  cache_if !condition, name, options, &block
end