Any handheld piece of technology that is old or outdated, like a cell phone or a offbrand mp3 player. The term comes from an episode of Tim And Eric Awesome Show Great Job that has a "commercial" that tries to peddle a ridiculously shitty cell phone.
Person One: Hey, bro, my cell phone just died. Can you mapquest directions to the party?
Person Two: Nah, sorry dude. I got the cinco phone.
Person One: Hey, can you take a picture of me here?
Person Two: Sorry, my cell phone doesn't have a camera.
Person One: You mean your Cinco Phone doesn't have a camera.