We recently had a requirement for sticky headers. This has become a popular UI style for scrolled interactions. Webkit now includes experimental native support for it via a CSS position:sticky. There are polyfills that can be used when its not available.

For notes and examples:
http://updates.html5rocks.com/2012/08/Stick-your-landings-position-sticky-lands-in-WebKit
http://philipwalton.github.io/polyfill/demos/position-sticky/