ElementStore is a stand alone implementation of jQuery.data().

jQuery.data() allows you to attach data of any type to DOM elements in a way that is safe from circular references and therefore from memory leaks.

Usage:
ElementStore.set(elm, "meaning of life", {42: 42})
ElementStore.get(elm, "meaning of life")
ElementStore.remove(elm, "meaning of life") //delete just one key
ElementStore.remove(elm) //delete all element keys

More info:
http://api.jquery.com/jQuery.data
http://amix.dk/blog/post/19504#ElementStore-Standalone-jQuery-data