I’ve just released another new beta version of Ambientweet.
You can now switch between the main tweet stream and a view which only includes your mentions - so that you can catch up on what people have been saying about you. Ambientweet also bounces the dock icon and shows a badge when it spots new, unread mentions.
In addition, you can now set Ambientweet’s window to auto-size. If you do this, it will keep the width that you gave it, but change height automatically so that the full text of the current tweet is always visible.