Creative iRoar + iRoar Rock Review @ Vortez
 

For that little extra thumping power, the iRoar can be docked in an iRoar Rock. The iRoar Rock is a 3.75" sub-woofer that expands the audio presence into a powerhouse of a sound system while fast-charging the iRoar. More interestingly Creative have more planned for the future in regards to companion devices for the iRoar and are working on a DDK (Docking Development Kit), potentially making the 'most intelligent speaker on the planet' also one of the most expandable and customisable.

http://www.vortez.net/review.php?id=1205