From last time I hacked something up with a Sphero [1] I remember having to lock the motors to read the raw gyro/acc data, this would make the ball itself quite unbalanced but it's an interesting idea nonetheless.

[1]: https://github.com/nmaggioni/flysphero

Totally unrelated question: according to Sphero website they charge you specifically for 1y/2y/3y warranties. I think in the EU at least this is not legal, 1y warranty from the producer is mandatory, and in some cases it must be 2. Obviously, covered by the price of the good.

There is no PC part. It is a standard Bluetooth mouse and works with any computer, tablet or phone with no additional software, as long as it supports the standard protocol.