Since there are so many questions about how people may reuse your work, have you considered a Creative Commons type statement of terms?

I am new here, and more of an engineer than an artist, so this is probably wrong. My understanding of your terms is that people may create derived works for personal or commercial purposes (preferably with attribution). People may use your work for personal purposes. People may not use your work to create a website of your work. (Do these conditions apply to any subsequent use of the work or derived works?)

This is very close to one of the Creative Commons standards. These give you a selection of licensing options and were designed for artistic works (see Creative Commons web site).

Richard Stallman's GPL licenses are designed for (intangible) software. GPL requires a strict separation between commercial works and GPL works. A GPL work is Free; anything made with it is GPL. (see the Free Software Foundation web site). The word Free means more than just price.

LGPL allows use of LGPL works as components within, but distinct from commercial works (such as a part of a mobile). LGPL requires attribution of the LGPL part of the work and that part of the work remains under LGPL licensing, as well as any license you apply to the entire work.

Thanks for the tips drbits. It is something we've been working on ourselves during the past year.

We've looked at using a Creative Commons style license, but the problem is that we in fact don't require attribution at all, and there doesn't seem to be any form of CC license that doesn't include at least some form of attribution as part of the terms.

We've contacted the CC in the past and discussed it with them. There is indeed a license in the making that omits attribution, but as of now it isn't ready for actual use.

Some GPL projects (like the game WarZone 2100) have also contacted us and asked us to release several photos under the GPL. One problem with switching the collection over to a new license is that we have to get permission from the people who donated their work to us. They have agreed to the terms as they are now, and maybe wouldn't be too happy when we switch to something like the GPL.

However, all the photos we've as the ImageAfter team have taken ourselves are in fact dual-licenced: once under the terms on this site, and once under the GPL. You can see our GPL compatible collection at http://gpl.imageafter.com. This site contains the better part of the main collection, and all images here can be used under the GPL.