Popup window como diseño dentro de la página web

Opciones para implementar:

http://prototype-window.xilinus.com/

http://www.pat-burt.com/web-development/how-to-do-a-css-popup-without-opening-a-new-window/

http://webdesignandsuch.com/how-to-create-a-popup-with-css-and-javascript/