Retirement/Pension Funds? Is it Needed?

To begin this discussion, I found video that fit.

http://www.youtube.com/watch?v=DC5R6oPwq74
The pension fund how does it work?
The point we entrust our money to the investment manager and can be taken after we retire and also their gain . The investment manager may invest in the stock or bond markets.

Needed?
Do not place the eggs in one basket, it should have a diversified investment portfolio, the pension fund is one of the diversifications.

How to prepare?
There are many institutions offering this pension fund, complete with the plan. Can immediately check it.

Science I still learning, so please if anyone want to add.