Creative Review - The Independent redesigns
Goodies « chris.ivarson
Gorgeous icons - good for Fluid apps
Iconic Icon Set
103 icons in raster and vector format — Some Random Dude
Simple Desktops
A collection of desktop wallpapers curated by Tom Watson to make your computer beautiful without distraction.
Icons for Interaction
Jon Hicks' @media 2009 slides
APNG - the animated PNG
Animated PNG files that retain backward compatibility with non-animated PNG files, w/support for 8-bit transparency and 24-bit images