Michael and Auriea wanted me to pass this along:

It's a button that will help you donate directly to Project Greenleaf, so that if you want to donate directly, or if you're a shopkeeper who wants to put part of your proceeds into Project Greenleaf.

Code:

<form action="https://www.paypal.com/cgi-bin/webscr" method="post">
<input type="hidden" name="cmd" value="_s-xclick">
<input type="hidden" name="hosted_button_id" value="6635598">
<input type="image" src="https://www.paypal.com/en_US/i/btn/btn_donate_SM.gif" border="0" name="submit" alt="PayPal - The safer, easier way to pay online!">
<img alt="" border="0" src="https://www.paypal.com/en_US/i/scr/pixel.gif" width="1" height="1">
</form>

Button: