Occasionally, taking notes from Aziz Ansari by way of Tom Haverford on Parks & Recreation can pay off in ways other than constantly treating yourself. Those with an encyclopedic knowledge of NBC sitcoms (everyone, I presume) will surely recall Tom's brilliant conversion of a simple Roomba vacuum into the incomparable DJ Roomba.
Likely sensing a need for the logical furthering of this creative ingenuity, an industrial designer from Utah modified the standard version of the Sphero (a robotic rolling toy that retails for around $130) to resemble the BB-8 droid you've seen rolling around in the new Star Wars: Episode VII — The Force Awakens footage. The designer added two magnets to the Sphero, connecting the original toy to the head he designed himself. For the skilled among us, the architect was thoughtful enough to link the world to a how-to guide in the description for his YouTube demo of the hacked Sphero (see below).
If building things yourself isn't exactly your cup of tea, you can just wait until Sphero releases their own BB-8 replica soon enough.