The worst thing is to bring your bluetooth speaker with you on an outing and realize you forgot to charge it or that your batteries are dead. In comes the Eton Rugged Rukus ($100). The Rukus is a solar powered, bluetooth enabled speaker. As long as there’s sun you have music and when it gets dark the Rukus has an internal lithium battery to keep you going. It can be charged via solar panels or a micro USB. The battery will last over 8 hours when fully charged. And don’t worry about a little abuse. The unit can withstand drops from 1 meter and is water resistant. So whether you want tunes for a camp fire or your hitting the trails, the Rukus will be able to provide the tunes.