Simple Image Gallery
This is an example of a simple image gallery. You could adapt this for use as a photo portfolio, for example. Pay attention to how margin, padding, and width interact to procude the "right" spacing.
We're using the Lightbox jQuery plugin to produce the popup. This plugin was (and is) so popular that many people now call this style of photo-based popup "a lightbox." If you're curious, you can read about this plugin's history on Wikipedia.