Usb Music Player?

I had an idea yesterday, what if there was a USB stick where you could download a song or sound onto it, and then be able to play that song with the click of a button on the stick. It could also slightly look like an iPod with a menu of the thing you downloaded, so you can play sound clips anywhere. It would probably take charge from a computer. The slider would be the screen, and the button to play the music would be on the right, and finally the arrows on the left.