http://asia.cnet.com/crave/2007/08/0...psule-speaker/
Actually, X-Mini is a counterpart of Hamburger Speaker only better in quality, durability and of course the quality of sound is superb for a size almost same as Golf Ball...Check the link above for reviews.
Note: Don't be fooled with fake Hamburger Speaker out there as cheap as P800...buy only a 100% genuine x-mini speaker.