Check out the Causes category in the library of themes for Firefox. You should really take that link, but here's a little sample of the artistic expression of some other movements.
We must be able to rock sweet life extension themes!
3827 active users!
1565 active users!
862 active users!
645 active users!
How we can create ImmInst personas:
"Personas are made up of two graphic image files - a 'header' image and a 'footer' image - which skin the default Firefox UI background."
The header should be 3000px wide x 200px high, the footer should be 3000px wide x 100px high.
"The right-hand side of the image should have the most important information - as a user increases the width of the browser window, the browser reveals more of the left-hand side of the image."
The images must be no larger than 300kb.
Anybody with an artistic sense interested in working on this? The top theme has 231919 active users: