Using WP-prettyPhoto is easy.

If you want to quickly add a lightbox functionnality to view your images in WordPress, I suggest you try WP-prettyPhoto by friend Pier-Luc. This plugin wraps the excellent prettyPhoto lightbox clone by other friend Stéphane Caron into a WordPress plugin with options and easy installation.

I recommend it because it took me about two minutes to setup here to my liking and because the styling is clean and the transitions are fast. Very neat. See examples below, two picture from my childhood in the 80′s.