This is one of my most wished-for features and I agree that the full feature as suggested by Nick would be best in order to offer maximum flexibility but as a placeholder, an interim step until a “fully customised sidebar” could be implemented, I would at least like to see the ability to simply hide those elements in the side bar that I never use which I assume would take less developer resource to implement so might be able to get into an earlier release. For me this would be useful because it would mean that on my iPad I could reduce the number of items on the side bar so that I could see everything I used without scrolling. It would also be useful on my iPhone.