I'm just a background hoarder. If I like an image I add it to my favorites and 99/100 times will add it to my background slideshow. I generally don't upload but if something catches my eye I will put it up if it's not here already. I also tend to go around adding sources and tags for backgrounds I know in order to give credible information or give credit to the actual artist.
As a mod: I mostly try to put anime in anime, general in general, and people in people. I also try to help out with dupes where possible. I leave the nasty business to the other mods.