I am seeing an emerging design pattern in web apps that is used for helping new users get oriented to a page or application.
It consists of showing a diagram with succinct helper-text over a semi-transparent overlay, sometimes with arrows pointing to specific controls on the page. One of the best example of this I have seen is in UX Pin, an online wireframing/design tool.
Has anyone ever utilized this pattern - and if so, what is it called? Or how did you refer to it?
I am also interested in learning how it is accomplished. Is there a tool or plug-in that might be useful for achieving this effect, and is it possible to do this in a reusable fashion without placing static text in a transparent png?