I heart all javascript developers who write OSS lightboxes for the rest of us, because a) they're really surprisingly difficult to do right in <i>exactly</i> the way you need it done (an edge case I've seen: does the content stay fixed while the grey overlay moves with the window when scrolled with the mousewheel on Google Chrome?) and b) proper integration of them with your site practically prints money.<p>You can look at the obvious one on my site for an example -- I've been through a dozen or so iterations of that, from starting with a simple HTML link to an image file (don't do this -- just don't) to a simple Lightbox for the image to the iBox for the image and call-to-action buttons that I'm using right now.  Those improvements move the needle for my business.