Back in 2005, Paul Solman--economics editor for PBS's NewsHour--filed this marvelous three-part series about possible avenues for Social Security reform. If you want a thoughtful video introduction to the heart of the problem, there really is no better resource of which I am aware.
The three segments examined each of the following possible alternatives:
1) Raising the retirement age
2) Lifting the cap on payroll taxes
3) Reducing retirement benefits