I've spent my time not studying for the past 24 hours and coded a jquery javascript file to add facebook-like dynamic image loading to zenphoto. Try it out (on any of the 33,000 photos) at t413.com. The current features for this are:

Loads any images' data a maximum of once per refresh, so no unnecessary server load.
Dynamic preloading (loads 2 images ahead, configurable)
Degradable. This is only an add-on. If JS is disabled then everything still works.
Keyboard navigation and click on the photo to advance.
Static linking enabled: each image still has its own url.
Back/forth still work.

There could easily be a lot more to integrate/do. I'm envisioning a built-in slideshow where it simply dims everything but the image and auto-advances.

What do you think?

Looks nice. How is it integrated? Is it a plugin or just themeing changes?

Right now it's just theming changes. If there's some interest I'd be happy to try to make it a plugin. The major problem I foresee is that each theme (mine included) has slightly different DOM layout than the next. I think a plugin could work for the default theme at least and then it could be integrated into others.

It's not that different from what the zpGalleriffic theme uses (the Gallerific script, which as additonally also thumbs)., isn't it? However nice and a theme or plugin with this would be welcome of course..;-)

timo: Are you going to publish your great theme for others? I would be very interested!