Something I miss everyday when using Firefox is Tabbed MDI (à la Visual Studio). I really hope this is something that will be implemented soon, because I often need to have two or more pages side-by-side. I do not want to open one more window - I already have enough windows on the desktop! - I just want to split the current one in two by dragging a tab to one side of the browser. I'm pretty sure this will be implemented in IE 7 (Could someone confirm this?). Please Firefox developers, include this.