Noteboard Foldable Pocket Whiteboard from ThinkGeek
http://www.thinkgeek.com/efc2?cpg=yt
-Folds up small enough to fit in your pocket, and big enough to cover a desk.
-Carry your notes with you and only write on as much space as you need.
-Includes a dry-erase marker (black) and a microfiber pouch (which doubles as an eraser).
-Blank on one side and printed with square-inch and square-centimeter grid on the other.
Dimensions:
-Folded: approx. 3" x 5" x 0.2"
-Unfolded: approx. 15" x 27"
Music by Magic Man "Polygons"
http://magicman.bandcamp.com/