That other thread (the spam one) made me wonder if you guys were sitting on any good sprite sites. A lot of the game development sites feature the same old sprites, or just enormous large archives with varying quality.
One I like is OpenGameArt
, easy to use and there are some pretty good sprites there aswell.
And another one
, this is just one large archive of sprites from the game AI War but it's really good.
I think I got both these from gamedev.net, but there's a lot of quite bad links to go through there before you get to the good ones.