Here is a portable DJ mixer that allows you to combine sounds from two audio devices including iPods, iPhones, music-enabled cell phones, mp3 players or just about anything audio device. The device comes equipped with two 3.5mm stereo inputs and a stereo output that lets you fade between both sources just like how a full-size DJ mixer is able to do. The Mix Tape Portable DJ Mixer needs two AAA batteries (not included) and retails for $30.