Created a couple rudimentary jQuery UI plugins up on GitHub recently that you might want to take a look at:

Follower

The follower plugin is a resilient, light-weight behavior. When applied to UI elements, it allows them to both retain their relative position on the page when “above the fold,” and automatically switch to static positioning when that element is scrolled out of the viewport.

PickSort

A sophisticated UI element used to elegantly sort a variety of items into different “baskets” or named containers.