Not that selection of webgallery for an Average Joe would be based on one single interaction, but still this is something to consider: In my default PC viewer(IrfanView) next picture is selected by simply using arrow keys. Also Facebook and Picasa has the same functionality. When using Flickr I have to use my mouse to click a small thumbnail to get next picture..
-So of to Picasa I go, thaks for great time Flickr. Disadvantages in this change are the looks and complexity of Picasa but advantages are simple and intuitive use and the fact that now I have all my stuff behind one Google account :)
