While we're waiting for Automator (and Tiger for that matter) to be released, I thought I'd throw together a few Workflows to put into our library. These will be simple, and likely have little impact in the annals of scripting history.
This first one I threw together in literally 20 seconds. It simply has you select a folder of images, which are then resized to 640 pixels (on the longest dimension), converted to Sepia via the Quartz filter, renamed sequentially as "Sepia-x" and saved in the folder of your choice. As with any workflow, you can change the settings so you're prompted for locations and filenames.