I have Photodeluxe 2 and Photoshop 5 LE, Dick. Pictures created in either have previews that can be viewed in either.

You're probably right about the invisibility of previews to browsers. However, I don't see how Adobe could prevent browsers from having access if the browser authors wanted to provide the facility. It's probably just one of those 'undocumented' aspects of graphics. There will probably be further standards developed in this area that address the need for a small pic for previewing that can be quickly expanded to full resolution by the viewer.

DonL