WPClipart - Public Domain Clipart
WP Clipart is an attempt to make a useful clipart package of public
domain images for use in word processors.  The collection contains
non-transparent PNG images, scaled down images, midtones expanded 
for inkjet print quality, etc.  The images found here can be used 
for any purpose without any conditions. 

The images install to /usr/share/wpclipart-$VERSION -- if there is 
a better location, someone enlighten us :)