X-Mini Capsule Speaker

The ultra-portable X-Mini Capsule Speaker, while still tiny, adds an expandable woofer that boasts immense sound for its size. Twisting the speaker opens an accordion-like patented bass enhancement to create even bigger resonance. A Red Dot award-winner, the speakers plug into laptops, mobile phones, gaming devices, and even link to each other for an on-the-go surround sound solution.

Rechargable through a USB cable, the super-useful range of five X-Mini speakers sell online for $20-80, depending on type.
X-Mini
Via [Cool Hunting]