Worth100 is the best site I've seen for Photoshopping (are we still allowed to call it that?) Their contests showcase beautiful, and technically amazing work. I've often browsed and wished I could do that.
Probably my favourite is this minature kitten (cute alert!) As with so many of the images, the detail and care given to making this look right is very impressive.
The image here is my own best attempt at this sort of image manipulation. Most of mine are made for Uncyclopedia, and sometimes bad quality is actually intended. But still, I aspire to Worth100.