Tshirt design legal issues

[Ferdinand Hagethorn <fer@terminal-ice.org>]

Hi there,

I've created a t-shirt design and i'd like to know if it's legal to
distribute this freely on the net for all diy'ers out there.
If it's not legal i'll pull it off immediately.
But if it's okay i'd like a disclaimer for people who will use the
images to make money (eg use them for commercial purposes) 
so that they'll send 1 US dollar per shirt to the Debian initiative. 
It the disclaimer i've put on the site sufficiant? If not i could use
some help here.
The text for the back of the shirt is 'apt-get into it' which is from a
banner made by someone at linux.com (found on the banner part of
debian.org)

Thanks for all your time and keep up the good n cool work.

Yours,

	Ferdinand Hagethorn