For some reason, there is no standard API to get the pixel coordinates of a DOM element relative to the upper-left corner of the document. APIs only exist to get coordinates relative to the offset parent. Problem is, it's very important to get those coordinates for applications such as drag and drop...

When we built the history management feature in ASP.NET Futures, we spent considerable time experimenting with the different behaviors of the main browsers out there. The problem with such a feature is that it has to rely on a number of hacks because browser vendors basically never anticipated this need...