Honest question: Do you actually use scroll bars much? I can't remember the last time I actually clicked on one with a mouse.
If I'm on a desktop, then I use the mousewheel for incremental scrolling and home/end/page/up/down for faster scrolling.
If you have a long page and your looking for something "about this far down the page", there should be a TOC or a map.
On touch interfaces, it's just the side of the screen or standard scroll.
At this point, for me, a scroll bar is more an read only position indicator than an actual navigation tool.
Interested to see if I'm in a minority here.