XORing bits to eliminate skew

[georgemw at speakeasy.net]

BTW, if the bits are assumed to be independent of
each other and you're only concerned with eliminating skew,
there's a well known simple scheme to eliminate it
entirely:

group the bits into pairs
if the pair is 00 or 11 toss it
if the pair is 01 map it to zero
if the pair is 10 map it to 1

this method gets you a fourfold reduction
in the number of bits in the best case.

George