Martian Blue has a very cool thread going on the UGO boards where he's posting custom items he's created and then gives you the text string you need to load it up as-is into your existing illustrations. It's a fantastic idea and I'm really glad he sent me the links.
Here's a sample helmet he put together:
Check out and bookmark the thread, I'm sure it'll turn into a wonderful resource for cool new items.
Thanks, Martian Blue!