Well, I'm not really sure if you will all make use of it, but seeing as how DR is the standard these days and his files are a huge mess (can't blame him, really, considering the way DF is developing), I have begun a project for a more coherent graphic file system.
Here it is:
http://mayday.w.staszic.waw.pl/~mayday/files/DF/graphics/ The "example" folder contains a zip with all the BMPs and the separate BMPs that are referenced in the graphics_example.txt.
The "undone" folder contains a list of creatures that have no graphics yet (mostly because they have been added recently).
NOTES:
-The graphics are created by DR, Tocky from pixeljoint and (in case of most military dwarves) my sorry self.
-Tocky's beautiful old-school sprites have been bastardized by me- you might want to revert to his originals: http://www.pixeljoint.com/pixelart/27171.htm#c138993
-The military units are placed in a specific order: Axe, hammer, mace, sword, spear, crossbow, fists, bow, pike, whip. When a race doesn't have a given unit, I place a blank tile there in case it's added later.
The categories are:
dorfs - obvious
animals- usual and giant animals
beasts- unnatural beasts and megabeasts
mans- monstermen
peoples- Humans, elves, goblins and kobolds
HELP:
You can help by looking through the files and notifying me on any mistakes I've made, posting suggestions on how to improve the system.
The missing creatures are a ridiculous case (tens of sharks and tens of gibbons, WTF?) and I'm pretty sure I'm not going to do them all until CORE51 is added. I may add a few creatures in case I encounter them in-game.