Just a short note about two great new imaging toys I’ve found recently:
Brilliant application which is now owned by google and has improved greatly since the first verison I tried - it now includes a search function and the star and label organisation system so you can highlight your favorite pictures and put them in virtual groups as well as in folders. It also now appears to have unlimited undo for any enhancements you make to the pictures - including the really easy to use rotating tool to sort out sloping pictures! (Picasa also produced the photo pile image at the top)
Generate your own landscape and render it - all the pictures included at the top I created using Terragen.