I created a little app to display a tool window on any website you want. The small widget is based on the great prototype window class by Sébastien Gruhier. I just made it work within a website with a little dirty iframe hack. You can see my work in action here. The very cool thing about this widget is, that it stays on top when your are navigation through a specific site.
This is just a proof of concept release. I will implement soon some improvments, flexibility in the code – maybe port it do java/jsp – and add some demo application that can be used with this widget. I will provide a download soon, so please don’t copy the stuff (source code is mostly viewable) right now.