xee

Xee is a lightweight, fast and convenient image viewer and browser. Even though the Mac OS comes with a picture viewer, I have installed xee because of it's capability to browse fast through a complete folder of pictures, which is not possible with the "built in" viewer of Mac OS.
Edit: removed on 17.11.2007 - Xee does not support Colorprofiles and I decided that with Leopard such an imageviewer is no longer needed for me.
Donationware