I guess it’s due to the major role that Automattic plays for the WordPress community that WordPress out of the box still doesn’t support local user avatars. Instead, users have to register with Automattic’s Gravatar to have a profile image displayed on their website (as long as the theme in use supports this). This is weird and a hassle.
While this is most probably solved with a little coding of your own, it’s also a niche for plugins – especially if you want your users to upload their pictures themselves.
The plugin with the most active installations, WP User Avatar, seems to do the job pretty good. Not acceptable in my opinion though is the fact that the plugin adds a new top level menu item in the WordPress admin bar – instead nesting into “Settings”, where settings like these should go.
This is really intrusive and displays a sense of entitlement by the developers that I can’t really understand. Of course, there are ways to clean up the WordPress dashboard – but why clutter it up in the first place? I really don’t get why this plugin is so widely recommended.
Enter the competition: The very similar named WP User Avatars has 10.000+ active installs and is actively maintained – by widely known WordPress core contributer John James Jacoby. This plugin may has less settings than the afore-mentioned one but it’s light-weight, fast and does the trick.