There is an interested product at Kickstarter called Tembo Trunks Earbud Speakers. What it will do is to amplify earbuds sounds as much as 3x from the original (80dB), so you can share it with your friends without clinging on each other when sharing music from one earbuds. Tembo Trunks is suitable for traveling or camping since you can ‘compress’ it smaller to fit in to your bag.
How to use it? All you have to do is to plug your earbuds into the provided notch at the rear side of the gramophone-like Tembo Trunks, and once you’ve tuned your song in your player, the Tembo Trunks will amplify the sound louder. Of course, you much adjust the volume of your earphones to max before you can hear anything good.
Tembo Trunks is made with high-grade silicone rubber, which make this accessories a waterproof, dustproof, shockproof and practically indestructible. I love the idea where you can actually pop it down to save space. I saw this Tembo Trunks as a successful project, as more than 442 backers has pledged $25,000+ to support this project. Their goal are to reach $10,000 funding, which is more than enough for them kickstart this project. However, if you still want to help, you can pledge more at KickStarter.