Anker makes some awesome bluetooth speakers, but this has to be one of the smallest I’ve seen. One of the smallest that actually sounds good, that is. It measures just 2.13 in. square, so it can easily travel in your backpack or large pocket. The sound is way better than you would expect from something this size, thanks to the 3 watt audio driver. Since it’s bluetooth, you can connect and control from up to 33 ft. away. Get that mini party started for $21.