We've seen many portable speaker solutions before. These Tembo Trunks, however, do things a whole other way: they work in conjunction with your earbuds.
First, they're not really speakers. Instead, they're sound amplifiers that take the waves coming from your earbuds, then pumps up the volume by 300% (around 80dB of clarity-enhanced stereo) using horn acoustics. While you won't be competing with the other tent's battery-powered 5W speakers when it comes to loudness, the product page claims it can deliver enough sound for plenty of casual situations.
The Tembo Trunks are horn speakers with a cone shape and an ear-like slot with lugs around the back for plugging an earbud (one earbud per speaker). Made from 100% high-grade silicone rubber (non-oil based) with no actual electronics inside, each speaker can be flattened for squeezing into your backpack, making it very convenient to bring along. Since it uses no power, you don't need to pack batteries, too, leaving you with a way to play mildly-loud music while everyone else's rechargeable speakers sit in their bags after a few hours of use.
Because everything is made of flexible rubber, the speakers are virtually indestructible (short of being thrown into a fire, that is). This makes them ideal as rugged outdoor gear for when you want to pollute the tranquility of the woods with Katy Perry singing Peacock (cockcockcock -- sorry, can't resist).
Unfortunately, the Tembo Trunks aren't available yet. Creators Mike and Scott Norrie, however, are hawking it at Kickstarter, trying to raise $10,000 to get production going. Minimum pledge is $39, which will get you a pair when the units are ready.