Hi, I've added a new functionality to my theme, to have a zoom effect on the thumbs (in album and search result pages) when the mouse stops on them. You can see how it works here:
http://www.antonioranesi.it/mamma_mia
This is a theme based mod, but if you like it I can make a plugin to have it working for almost every official theme of zenphoto.
I'm testing the plugin right now, it can work without theme support using an ajax call.