Hey dude,
obviously - Solely DBP related stuff in DBP, DB in DB, Dark Physics in dark physics, thats all bloody obvious, not gonna patronise any more, 3D Chat is basically the 3D modelling section, 2D chat I guess discusses 2D techniques, General talk/geek culture is your unrelated section if you like, or your 'others'
In this area I haven't seen much in the likes of sky boxes, something I might consider using as place holders if I ever get that far in a project
But the textures could be stolen for renders/test renders.