One man’s useless machine is another man’s treasure… or something. [Matt] shared a link to his MP3 gr3nade in the comments of our useless machines post. The project took a decomissioned hand grenade and shoehorned an MP3 player into it. His decision to locate the headphone jack where the safety pin goes is a nice touch.

This reminds us of the boss from a previous job who had a chrome plated hand grenade on his desk.  Now that was a useless object (and a useless boss). This project actually does something, but are you really going to ride around on the subway rockin’ out to the Bee Gees while holding a hand grenade?