Today F-Spot has a browser mode, where you see all photos as small icons, or
Edit mode where you only see one photo.

On the top of the main window you see a timeline with an indication of how many
photos per day.

I would suggest we add an option to in Edit mode, we add one slider with small
photo icons to indicate which photos are before and after this one. Also
possible to use the slider and do a "fast scroll" forward or backwards to find a
particular photo when in Edit mode. 

This is the way Aperture  (http://www.apple.com/aperture/) as well as Lightroom
(http://labs.macromedia.com/technologies/lightroom) is working.