I tried setting it up a while back and was unsuccessful in getting it to work in my configuration. I use Embperl as my templating system, and, for some reason, Apache::Session::memcached would not cooperate with Embperl. Nobody here (PM) had any answers, neither the embperl or memcached lists was helpful, and I had to move on. I was able to access the memcached in other ways, just not through embperl. See this node.