jQuery.positionSticky is a sticky positioning polyfill for jQuery. Support for display and float properties example and sidebar example included.
Sticky Sidebar is a jQuery plugin for sticky/fixed contents (headers, sidebars, footer, etc...)
fixto is a jQuery plugin for sticky positioning. Fix containers to the viewport relative to an ancestor.
jQuery lockfixed allows for DOM elements to be positioned anywhere on the page, and lock within the user's viewport when scrolling. Common use case is a menu under a header, which on scrolling stays fixed within the viewport.
scrollNav is a light jQuery plugin that grabs your page's existing content, divides it up into logical sections and builds a customizable scrolling sidebar navigation.
jQuery Stick 'em plugin makes items sticky as you scroll, to a point. Easy to implement and flawless to the point of perfection, this is indeed a very useful plugin.
stickyMojo is a contained sticky sidebar plugin for jQuery. It is lightweight, fast, flexible and compatible with Firefox, Chrome, Safari, and IE8+. It will degrade gracefully in older versions of IE.