In Chrome we have an extension that helps to navigate through a gallery of images, the Gallery Helper. It increments the last number on the URL so you can access the next image.
We also have Filter Images that opens any image greater than a predefined size in a new window.
For Firefox we have a better one called Browse Images that gives you a keyboard shortcut for going to the next image in the gallery and even has a downloader for all images in a gallery.
I need to find more of these tools, specially one that allowed me to download all images in a gallery, even if each thumb in this gallery linked to a page displaying the full picture (as opposed to direct link to the picture itself).
Do you have any suggestions?