I know this video player can not insert to your wallet, but i think it is small enough for your pocket. This credit card size video player comes with 2GB built-in memory and available in two LCD size: 2.4-inch or 2.8-inch.
Product Features: Mini Media Players Handle Video, Audio and can do Voice Recording, Keys on Neon M3 are heat sensitive and glow when touched, Built in FM Radio, Integrated Speaker, or use the included Headphones.
Via gizmosforgeeks