Today I found a script which replaces Lightbox, Graybox, Slimbox etc. It’s called FancyBox and different although doing quite the same like the rest. However, I like it because of its high customization and ease of use. Transitions are smooth and beautiful even on lower-end machines, galleries can be scrolled through using your mouse-wheel and it even supports external content using an iframe in an overlay on top and separated from your own content.
Feel free to check it out here.