I'll accept photos, but not photomanipulations unless you take all the base photos yourself. I'll update the rules to accommodate this, since I simply said "no photomanipulations." The trouble with photomanips is that it's near impossible to tell how much of the work is your own and how much is borrowed to create it.
As long as you take the original base photo and don't use too much stock to add onto it (or simply make your own changes in Photoshop or what-have-you without additional stock), then that is fine.