One of the best selling cell phones ever built, the Moto RAZR is also one of the most well-known phones. At it's release, the RAZR was remarkably thin at 13.9 mm. Though it's still among the thinnest, there are many other phones that are thinner, or as thin.
It's predecessors were both marketed as fashion phones, selling for $500 or more. The V3, however, was introduced at $250, and now is sold for for $50 or less on the open market.
The RAZR V3 also introduced many smartphone features to the consumer phone market, such as a calendar, and Bluetooth.