Wed Jul 11 13:33:25 EDT 2012

Counter bitswapper

It seems that picking a random bit from a set of bits can be
represented much more efficiently using a counter.  Keep track only of
the number of bits that are in the bucket, then randomly generate a 0
or 1 based on this level and update the counter.

If this behaves the same, then the "impulse response" should be the
same also.  Though I don't see a way of how to compute it.