I'm looking for examples of designs where there is special logic that prevents a title, heading, or landmark from being moved out of view, so that the user doesn't lose their context.
- Excel's "Freeze top row"
- iOS UITableView (notice the "A" subheading floats)
What are some other examples? I'm especially interested in examples that handle more complex situations than simple tables. For example, a graphical app where the user can scroll in a more freeform way, or where multiple headers can be floating at once.