JQueryStuck is a project mainly written in ..., it's free.
A delimiter-capable, event-firing, multiple-instance-wielding sticky sidebar plugin for jQuery.
jQuery Stuck aims to facilitate keeping a sidebar item visible when the user scrolls past it, with the (entirely optional!) ability to constrain its movement within a container box so that it doesn’t interfere with a footer-type div. It will also fire a series of custom events, allowing the developer to assign custom functions to the events (for the time being, it only fires one event: reachedBottom. More are in the works.)
Finally, I’m hoping for it to also allow multiple objects to be stuck, so that section-specific sidebar items can stay with the user only as long as the relevant section is in view, then stop and allow other section-specific sidebar items to stay in view as the user scrolls down.
Since this plugin is not yet production-ready, I won’t bother with usage instructions yet. The test.html provides a good example of usage. Please feel free to fork/download and fiddle with it to your heart’s content.
First official version, derived from some (shamelessly dirty) custom scripting for VorticeOnline.com.
jQuery Stuck Plugin is licensed under the MIT License, except in the case of blocking a double flying kick to the chest. There is no way that you’re gonna block a double flying kick to the chest with software, so really I’m just saving you the effort.