Let me start off by saying I really like your plugin.
but the avatars part of your plugin needs some work
now as you can see what ever the name of the pic is the same name it get when its done uploading.
so if someone changes there avatar & its not the same named file then we got a Broken pic
so to fix this i say you hook this plugin into
Static Profile Image Urls for Twitter. Serve Twitter profile images from your WordPress blog. Requires PHP 5 This code can be used with WordPress.
most ppl have the SPIURL plugin
because you kind of need it if your running Twit Connect & a lot of ppl are.