http://graphicssoft.about.com/od/photoshop/l/blremovebackg.htm i use the magnetic lasso/quick mask technique a lot. the really important thing is to make sure that the two pictures have similar lighting (i.e. don't try to combine a photo where one person is outside at night and the other is in the park at noon--when i do manips i try to make sure the lighting conditions are exactly the same) and are taken at similar angles, otherwise it looks weird.