I don't know much about what I pick when I upload a picture...I just kind of click away so as to share my images as fast as possible. I want it to be known that provided you tell me what it's being used for, all members of Newgrounds are welcome to use my images freely for whatever purpose! Of course, don't bother asking if you want it to be your background...that's...kind of what they're there for to begin with =P
Cheers,
Mike