I recently added a widget to this blog and struggled to find a way to maintain the scroll position after clicking submit. It turns out this is an incredibly easy thing to do (once you find it). All that I needed to do was add the following to the code behind of my master page.
Page.MaintainScrollPositionOnPostback = true;
It requires java script to be enabled; however, it works very well. In searching for how to do this I found many other solutions, most of which were much more complicated and involved. Though I am not sure this is the best way, it works for what I needed.