If you haven't already tried it, I suggest viewing the gallery in Firefox with the new CoolIris PictLens plugin. You'll see a "3D Wall" of images, complete with a slideshow feature. You can download Firefox here, and the CoolIris plugin here.

After everything is installed, go into a gallery and click the "View Slideshow" link in blue at the top of the page.

CoolIris can be easily enabled/disabled from Firefox's Tools > Add-ons menu.