Yeah... that link sure is hidden... "ubuntu donate" + I'm feeling lucky = http://www.ubuntu.com/community/get-involved/donate
It's not like having an address in the forum sig hurts anyone, so why do you care. I find it much less annoying than the large banner ads for pyramid schemes.
my question was this, do you see anywhere on the front page of ubuntu where it says "donate" or something. the fact is, you still used google to find the link, and that proves my point.