I was interested in the flywheel concept of doing KERS. Put simply using the braking forces to spin up a flywheel at ridiculously high RPM's and then tapping into that rotational energy when you needed a boost. Not sure how it worked, basically the flywheel was just the storage method instead of a battery or super-capacitor.
It throws up loads of interesting questions about gyroscopic forces...
I didn't even know Williams were going down a route of doing KERS like that. It's an interesting concept. Maybe that's why they really don't want it to go away for 2010, they've been developing this for next season and have found it to be useful compared to regular KERS.
I really do hope KERS comes back for next season, gives alot of talking points and is food for thought.