Check out this ajax photogallery: minishowcase. It’s lightweight, easy to customize, and a piece of cake to get up an running in no time. I removed the enormous Gallery2 from my server and replaced it with minishowcase. I lost the theming of Gallery 2, but minishowcase theming is on the way, and it wouldn’t take much to create your own from scratch. Download also included easy to customize .css file.
For now it is fully functional in its own page here, but I will intgrate it as time permits.