Just today while looking for new JQuery plugins, I ran into two interesting lightbox options. ColorBox is a lightweight option with some useful additional features; jboxed is another option that does things a bit differently with a unique navigation style not too common for most lightbox solutions.
Some useful links for UI and navigation, utilizing jQuery:
Too many lightbox thingies to choose from? I personally like Shadowbox for the many things it can do but there are several others that do well for certain purposes. To help you find the one that fits your needs, the lightbox clones matrix lists the popular options along with its dependencies, capabilities, and the actual library size you’ll be adding to your markup. Helpful!