Doubleofive:
So legally (or contractually), no one could use your mattes unless you were getting paid? Man, that sucks. Guess it comes with the "job in the industry" territory.
Most work I do (none yet posted here) is work-related so obviously I can't share that. But the stuff I do for fun, some of it posted here, I probably wouldn't give out the full-res version unless it was for someone to use in a good project. I'm happy to post low-res, desktop-sized versions, but at the same time they really don't do justice to something that was painted with 30-40 times more detail hehe.
I know some people think that, because the stuff we post on here is inspired or even "photoshopped" from someone else's material, that we don't own it, but that's not the case. The Endor night matte I did, for example; WE know it's Endor, but there's nothing in that image that isn't mine or altered drastically from its original version, so I own the image entirely. It's a legally complex area, but generally, if you change someone else's image significantly then you are not infringing.
So with that in mind, get painting, you lot!
I think we should have a contest on the forum sometime, for people who haven't posted before, or posted much, with some sort of prize for the winner. I really want to see what other people can do.