Jquery help overlay interface

I'm really curious to know which one of them made a jquery plugin to add help overlays that can be anchored to a floating position next to elements on a web page.

The idea would be that when the help button is clicked (or the first time the page is loaded), blurring the page and overlaying key elements is descriptive text that explains what these key page features do. Ideally it might even be step by step so you can illustrate the functions once with next / previous navigation showing somewhere.

Great examples of these can now be found in Gmail. The snapshot is at the top of this page: http://blogs.clariusconsulting.net/kzu/documenting-user-interfaces-in-a-mouse-less-touch-ui/

They don't use jquery and I assume they are hardcoded. If anyone knows of a flexible jquery plugin that can do this, or something similar magically, just by specifying object IDs on your page, please share.