Well having a teenager... the "dress up" part will have to be minimal. My daughter came up with the idea of "Facebook"... but her idea was to just walk around with a book and when asked "What are you?" she would put the book up to her face and reply, "Facebook!". Good idea but not a good costume... so Mom took it to the next level.
I created a trompe l'oeil headpiece which was an image of a book...complete with real looking pages. Didn't want to have any Facebook logos or text on the book. It is meant to be uber-simple. She placed her face through the hole and at the back there was a cardboard strap to keep it in place on her head. She wore black.
This Homemade Facebook Halloween Costume is really easy....all you need is scissors, markers, scotch tape, glue, poster boards and a flat screen TV box. Magazine optional.
Cover entire TV box after facebook profile pic hole is cut out. Cover entire box with poster board. Glue and tape it down. You can use magazine for advertisments on the sides of the box. Then go onto your facebook and draw what you see on your page. That's easy!!