... , TV, PSP .etc 5.Smaller size, longer using time. More portable, more personalized. 6.With Built-in high capacity rechargeable lithium ... battery and USB charging connection, you can use it more portable along with computer, cell phone, PSP, MID, MP3, MP4, and ... . small size, more portable, more humane, out of the limitations of USB-powered, not just only used in notebook or desktop speakers ...