If you use iPhoto and post images from it to a Gallery2 website then Karl’s post here might be of interest. See XK72 Spacelab – blog of Karl von Randow » Blog Archive » Gallery iPhoto Exporter
Gallery iPhoto Exporter
Gallery2Export is a plugin for iPhoto that enables you to export photos directly from iPhoto into your Gallery2 website. It was originally developed by Dustin Brewer, based on the Flickr and Coppermine iPhoto Exporters.
BTW – Gallery is an open-source web-based photo album organiser. (You don’t have to run iPhoto to use it).