Here's a Joe Gagan Easy Face with a variable input cap. Doodle enclosure done with red and black Sharpies.
(http://www.super-freq.com/wp-content/uploads/2010/09/IMG_2765-e1285473089395.jpg)
(http://www.super-freq.com/wp-content/uploads/2010/09/IMG_2767.jpg)
(http://www.super-freq.com/wp-content/uploads/2010/09/IMG_2768.jpg)
(http://www.super-freq.com/wp-content/uploads/2010/09/IMG_2769.jpg)