I am not that much of a tech head to have ever been aware of the Expires header, Keep-Alive, etc …
But I do know that the simplest and fastest way to display avatars is from my own server. Because WP is free, and incredibly popular, use of gravatars out here is simply to keep WP’s overhead costs down. It just makes profile editing more complicated than it needs to be because you have to set up another account and there are no instructions on our WP Profile edit pages to direct users to gravatar.com to post a “universal” avatar.
So, in terms of our own blogs, on our own sites, is there a way to simply an avatar image, from our own server or external url, without using gravatars?