More information isn't always better, at least when it comes to revealing employee salaries.
I agree with Tim Low's points as a compensation specialist. In fact, we have recently consulted to several larger organizations addressing this very challenge.
That said, we feel that general access to pay-grade information is probably sufficient. There are too many variables in terms of tenure, skill sets requirements, etc to make total compensation transparency viable in most organizations. The practice creates ceilings and can reduce top employee performance incentive. They are NEVER created equal.
A few exceptions might be sales centric organizations like sales reps.
But, as soon as everyone in the company knows what the CEO makes, the culture begins to implode with resentment.