I am re-evaluating our department's attendance policy and protocol for employees calling in to work sick, car trouble, drunk, [insert excuse here], etc...

If an employee is going to be late or absent, we require them to call the office before their shift starts, and leave a message if no one answers. We have split weekend crews that alternate weekends, and if they miss their scheduled weekend shift, they have to make it up the following weekend. This seems to help deter many weekend call-ins. But, when we come into work to find a message that was left @ 1AM Sat/Sun morning, I usually suspect they've just been out all night, and don't even intend to get up early that next morning. I've thought about requiring them call in at a more specific time - like no sooner than one hour before shift start....that way they have to get up at their scheduled time anyway.
We currently use progressive discipline to deal with problem employees, and keep detailed records...the goal is to be fair and consistent. However, these types of systems can be subjective, biased, and inconsistent, varying with each manager's personality/mood, each employee's recent history/attitude, severity of the problem, etc.... fluctuating seasonally, and especially over the course of months and years.
I've considered implementing a point system, clearly outlining disciplinary actions...and possibly provide an incentive to those that haven't accrued any points over a specified time period. A well-planned point system might create a more consistent disciplinary process regarding attendance issues and create more motivation to be more dependable...
I feel that having a job and getting a paycheck for doing something I love is more than enough motivation to get me out of bed every morning....just wish some of my employees felt that way. It seems more people are adopting the mindset that a paycheck is a given, and they expect rewards and incentives to perform and simply fulfill their job responsibilities. Is the English proverb "You'll catch more flies with honey than vinegar" more applicable today?
I think with so many people out of work, I can just as easily fill a position with another good individual. On the other hand, I don't want my strict policies to create high turnover since our entry level positions don't exactly attract the cream of the crop per se.
What are your specific policies, ideas, opinions, etc....How do you deal with these problems? Where do you draw the line?