Stick-On Cardstick, One Twelfth of a Yardstick

Many things claim to be credit-card sized, but none can be more perfectly exact than the Cardstick, a ruler that sticks onto your actual credit card, and is therefore atom-for-atom the exact same size as that card (if you ignore the fact that it adds a little depth to one end of the card).
Further, because [...]

Source: http://www.wired.com/gadgetlab/2011/08/stick-on-cardstick-one-twelfth-of-a-yardstick/

sony ericsson x10 song ericsson xperia saamsung galaxy s sampsung galaxy s