Wordpress plugin floating sidebar widget for individual posts

I need a Wordpress 3.0 plugin which will provide a floating sidebar any html code widget which moves down very smoothly (flash video in the widget should move down smoothly) in all browsers above the other widgets in the sidebar as we scroll down only for the individual wordpress posts and pages. I should be able to add different html flash video code in the widget for displaying on different posts and pages i.e. each post and page can show a different html code in this widget. This widget should not appear on the index, archive, search etc. pages. It should preferably use as lightweight javascript files and code as possible which should be cachable by the standard wp super cache wordpress plugin.