Quick question - I have 2 arrays, one which holds the list of people who 
had access to a system when I last checked (OLD), and and another which 
is the current list of people who should have access (NEW).

Is there some neat syntax in Ruby which would allow me to find the 
people added in NEW who are not in OLD, and then find the people in OLD 
who have need to be delete as they are not in NEW?

I was going to sort the arrays and iterate through them looking for 
differences, but I suspect there is a really cool Ruby syntax to achieve 
this.. what is it?
Thx
Graham