You might have read about this already as you have mentioned in your question.
I would like to emphasis the importance of safety and tell you what might happen in case of a fault in the power supply circuit.
Let us imagine that the line (L) (also called "phase") touches the body of the SMPS inside your computer, in that case the body of the computer gets energized. Any one coming in contact with the body of the computer (or with any metallic peripherals attached to it) may receive an electric shock. If the person coming in contact is wet, this electric shock may prove fatal.
In case where the earth pin is connected to the ground (earth), this fault current would flow to the earth (as it is the path of least resistance).
With a leakage current (or with the body energized), the body of the equipment is at a certain potential with respect to the ground. Motherboards (for example) operate at +12V and +5V DC potentials. Now whenever there is a faulty contact established between the body of the equipment and its component (in this case, the motherboard), it is going to see a potential something other than its operating voltage. This can harm the motherboard and it might stop working (in some cases - it happened with me!)
Buy a three pin socket, wire the phase and neutral lines from your un-grounded outlet. For the earth connection draw a wire from the nearest grounded outlet or from the earth pit (you must have one in your residence).
Connect your surge protector to this new three pin socket.
Do not try to change the wiring of the house on your own if you don;t have any experience in wiring electrical circuits. Many other appliances may stop working if you mess up or worse you might receive an electric shock if you do not know what you are doing