But so far I've only managed to pick up some 
Angelic Layer douga.  I keep being just a 
*little* too late on the Taro RX updates, it's 
getting really annoying.  Want Rah Xephon 
sketches of the pretty characters! *sigh*  Angel 
Sanctuary is also far up in my wishlist, I love 
the character designs.

Some CG shows seem to be fairly common, though.  
Mahou Tsukai Tai! sketches seem easy enough to 
find on Japanese sites at least, and I've seen at 
least one site offering massive amounts of 
Kamekaze Kaitou Jeanne douga.