Explaining JavaScript scope and closures

Closures are a critical part of JavaScript libraries; this tutorial explains scope and closures: http://robertnyman.com/2008/10/09/explaining-javascript-scope-and-closures/

Another great article on the same subject from the always impressive SmashingMagazine.com: http://www.smashingmagazine.com/2009/08/01/what-you-need-to-know-about-javascript-scope/

And more here: http://blog.morrisjohns.com/javascript_closures_for_dummies.html