Having recently met some success in transmogrifying game sprites from old classics into Dominions 2 units I thought I should share that idea with the rest of you. I know Illwinter might not approve of using graphics from another game, even pretty old ones, but you haven't truly seen Dominions 2 until you had the entire cast of X-Men taking on the forces of R'lyeh and win!
I know it's completely silly but sometimes you need the comic relief.
Here's the page were I found most of the grapics I use in my mods. There are tons of game sprite sites out there though.
http://www.flashstand.com/sprites.php?mode=misc