sometimes, I feel as though I should be carrying around a spiral notebook, so I can note each heinous grievance between my children. Example, at lunch today, child #2 got to sit in the corner seat, child #1 melted down and claims that next time is his turn. Or, at the grocery store, one kid gets to hold on to the handle of the shopping cart, the other is totally slighted.
If I had a little notebook, I could keep track of all this inequality and the next time we were faced with the tough decision about who gets to sit by the window on the plane flight, I could pull out the little book as a reference..."well, I show that in June of 2006, on our way to Minnesota, on the flight between Denver and Minneapolis, you sat next to the window, so now it is now your brother's turn".
I am sure this system would help.