Cool, but just in theory because of IE compatibility issues.<p>Hmm, I wonder if you could have done this without :target, using a:active. Drop an element inside of a link that is the lightbox container (#lightbox_container), set to display: none. Then, a#lightbox_link:active #lightbox_container would be display:block;.<p>I'm on my way out, but maybe I'll try it out when I get back. Using position: fixed on the lightbox container, it'd be IE7+ compatible. Position:absolute would be IE6+.
Interesting, but the back button in Safari 4 goes back through all the futureboxes that were popped up and closed previously, as if each were its own page. Really annoyed me...