Turning your cell phone screen into a mirror

Senko's ScreenMirrors are transparent films that produce a high quality mirror effect when a screen's backlight is off, but allow for clear display visibility when the backlight is on.
"When the phone's backlight is on, you can see the screen beneath the sticker — but only if you're holding the phone within a 45° cone. The "advantage" of this specific angle feature is that nobody to either side of you can see what you're doing with your phone".
[via Sci Fi Tech]
Other cell phones with mirrors:
-- The ELLE Glamphone is a stylish mobile camera phone packed with an array of feature included a screen which converts to a mirror when not in use.
-- Motorola's Boost Mobile i285has a discreet vanity mirror located inside the handset's back cover.