On a photosharing site like flickr, images are resized down to 500 pixels (longest dimension) for basic viewing, thus you can upload images 500 pixels wide and not change how most view the photo.
3) A Note on Color Profiles: Much of the internet currently lacks color management (for more information see my article on Soft Proofing and Color Management for the internet).
To quarter an image in Photoshop create vertical and horizontal guides using View-Guides should be checked to make selections easier) into new files.
These images can the be re-assembled within a table without cellpadding or cellspacing (the 'vertical-align:bottom' style should be applied to the images).
These short scripts over-ride browser right clicks.