I've noticed that there are enormous amounts of stock images out there - see, for example, the relevant category on DeviantArt. But they have the same problem as online tutorials - there are so many of them that finding the precise stock image you need is exceedingly difficult.
Thus, creating a stock image directory within the wiki would be a good possible expansion. Of course, this would require creating a entirely new directory structure for them - and then adding links to stock images out there, ideally by the creators of those stock images themselves. This could become a very useful resource for those needing such stock images.
However, this is an undertaking to which I can contribute little - my limited time is mostly dedicated to adding more tutorials, and since I don't use stock images myself I wouldn't know how to categorize them. I can help with setting the categories up, but that's it. To really get this underway, I'd need one or more volunteers who would be willing to add new links to this directory, notify stock photographers of the existence of the directory, and work with them to add their images.
Is anyone interested?