Apparently a smaller MP3 player is more convenient to carry. The sugar cube-size Kube tiny MP3 player is the best proof, only don’t put it in your mouth, it’s not waterproof.
Kube is a worthy tiny MP3 player. It measures less 1-inches tall, weights 18g. The mini cube has a 2GB microSD card. Through the integrated microSD card slot, the storage capacity can expand to 32GB. The built-in rechargeable lithium battery can offer up to 6 hours of continuous playback after fully charging through USB cable.
Kube tiny MP3 player is available in five bright colors, including yellow, green, pink, white, and black. Each one costs $34.99 USD. If you like the mini MP3 player, jump to ThinkGeek for more details or grabbing one.
additionally, here is a sugar cube-size tiny speaker.