The following text was found on Xach Beane’s great GIMP News website.
From Jonas Oberg comes this request:
The GNU Project webmasters are looking for artists
that can contribute to the GNU Project. We are interested in
pictures that are related in some way to the Free Software
Foundation, the GNU Project or the free software movement in
general. On our web page, http://www.gnu.org/graphics/graphics.html,
can be found a brief list of graphics that we currently use. Please
help us expand that list by contributing graphics. You may send any
graphics to webmasters@gnu.org and we will
consider it. If the graphics is large you can put it on some ftp or
webserver and send us only the link to the files.