We are faced with an issue of convenience versus freedom when we talk about licensing images. Because we are a nonprofit charitable organization with an educational mission, we can easily get non-free licenses to use images.
This is easily done, but doesn't achieve the goal of building a free encyclopedia. There is no help for it; to make a free encyclopedia, one must stick to materials that are free.
Because we are a nonprofit charitable organization with an educational mission, we can make heavy use of the doctrine of "fair use" in the US.
When applicable, this may be a good solution.
Clause 7 of the license permits us to combine independent works, even proprietary works, and this clearly includes aggregating images and articles stored on the same server.
This is permitted in the sense that it won't violate the GFDL. But when the other work is not free, this is not a solution--not if the problem is how to make a better free encyclopedia. Including non-free images, whether done legally or not, results in a non-free encyclopedia.
If that means less images for now, then it means less images for now. It also means that we have a very strong incentive to develop free alternatives.
Hear, hear!
In many cases, people can creatively find ways to take new photos.
Another idea is to criticize the organization that stands in the way of using the image desired. For instance,
The Foobar company stands in the way of our including a picture of this.
This text, with no link and no details about the image, would name and shame the Foobar company, but would not help Foobar sell copies of the image.