I pushed out a quick update to ER Tweet Me yesterday (now version 1.1.1). Now URLs are automatically linked up if they are not already a link. If the twitter feed you're pulling in somehow already turns URLs into live links then it should not have any negative effect. So, go download and enjoy the new update. Remember, it's compatible with both EE 1.6.x and EE 2.x (since the 1.1.0 release).