I have a friend whom wrote a system where eveyrone starts off with a moral 50 on a 1 to 100 chart. A dozen or so broad actions were given positives to range morals and a dozen negatives. They were broad enough to not require lots of micromanagement such as help inniocents, save town, lie for self (negative), kill for self .
It's pretty good and something i plan on adding to my next campaign if 4e doesn't have a solid allignment system. Moral score is usually handled and scored by the pc except specific incidents where the dm will have to rule on a moral consequence). How the pcs play it is up to them, but certain spells and abilities either work or don't work based on where the moral score is. Like a cleric of a good god must be at 60+ to cast spells whereas he can only heal those 40+. It goes something like
I cast heal, can my cleric heal you (yes/no).