Hi Jane:
There are serveral third-party packages that convert images in batches. You may want to check out some of the shareware and freeware sites such as WinPlanet.com, Downloads.com, Tucows.com. The other option to have someone to write a script to automate the process for you. I'm sure you could find a local Perl programmer who could write something quickly.
You can also check out some of these products in the SmallBusinessComputing.com and ECommerce Guide Product Watch sections.
http://products.ecommerce-guide.com/...g/recent1.html
http://products.smallbusinesscomputi...w/recent1.html
Dan Muse
Executive Editor
internet.com's Small Business Channel