I realize that there are differing views on whether or not vinegar is
considered paleo -- some say no way, others say ok if made from paleo
sources.  For those of you in the latter camp who enjoy vinegar, take a
look at the study below concerning vinegar and improved insulin sensitivity
in type 2 diabetics and those with insulin resistance followin high carb
meals.  (Maybe this is part of the reason Japanese can eat so much white
rice and stay slim? They put vinegar and/or pickles in nearly everything.
Just a thought)

Vinegar improves insulin sensitivity to a high-carbohydrate meal in
subjects with insulin resistance or type 2 diabetes - Observations
Diabetes Care,  Jan, 2004  by Carol S. Johnston,  Cindy M. Kim,  Amanda J.
Buller
http://www.findarticles.com/p/articles/mi_m0CUH/is_1_27/ai_112312372