Dundjinni Ratio and Sizing

5 scale feet = 200 pixels (PNG) = 1" printed (battle map).
For smaller artwork, like knitting needles, balls of yarn, etc. It's suggested that you use this format, and let the person who uses the art scale it down to size in Dundjinni.

Creating PNG files w/Adobe Illustrator & Photoshop

This post is for anyone who wants to create User Art for any program or company that takes PNG files.

(Including myself, the often confused as a reference.)

First create your object in Adobe Illustrator.
Second, save it. (I work with AI. 8 a lot, so that's the file version I should save it down to.)
200 DPI for objects, 150 dpi for floor and walls.

Adobe Photoshop version 7.0, Open your artwork as an EPS (straight .ai file)
Convert to RGB.

Add ghost shadows to create object depth. The shorter/longer the shadow is the greater the height & depth of the object is implied.
If your doing something flat, like a piece of computer paper, or a credit card, you probably won't need to add shadows.

dblade recommends for the PNG save I would be using the Save for Web function in Adobe ImageReady and changing the output to PNG-24. Make sure Set as Transparency box is checkmarked.

Save as a copy to PNG format.
Backup finished work on cd disk, and upload your contribution to the server.
I suggest that you choose and keep a separate CD original .ai file, and PNG file together on disk.