Simple Modal Boxes: FaceBox with Prototype (with OSS code) (blog.japanesetesting.com)

I'm a big fan of light boxes -- they let you get you stuff even more copywriting stuff above the fold without burying the signup form beyond a page load. My feeling is that they work better than standard signup forms but I don't have any A/B tests to back that up at the moment. Hmm, must put that on my list...

With jquery UI:

  <div id="foo"></div>

  $('#foo').dialog({modal: true});

One could tweet jquery tutorials, that's how beautiful it is.