I just released jQuery Metadata 2.1, which adds support for HTML5 data-*. Usage:
<p id="one" class="some_class" data-item_id="1" data-item_label="Label">This is a p</p>; $.metadata.setType("html5") $("#one").metadata().item_id == 1; $("#one").metadata().item_label == "Label"; Get it at http://plugins.jquery.com/project/metadata -- Yehuda Katz Developer | Engine Yard (ph) 718.877.1325