lanyard connector and headphone jack on one end of thebrick (the microSD card slot sits at the other end): The Brando Homade MP3 i-Player ($45) can be shipped anywhere in the world for $3.

The build uses an Arduino, an MP3 chip, a SD card, LCD screen, amplifier, and two speakers. Everything is then packed into a small repurposed box with buttons and a volume knob. The end result is ...