Penalty kicks are rather easy to score and save in FIFA 08. Because fouls are so frequent in online play in FIFA 08, you ought to know how to do both. There are three ways to score penalty kicks:
To execute a regular penalty, press the same button that you use to shoot normally on your particular gaming console. The best amount of power to use is just enough so that you can see a bit of red, but not a lot. Experiment in the arena to perfect this. Use the analog stick to aim, you don't have much control over anything but left or right with the analog stick, the power of your shot determines the height and of course the power.
To execute a placed penalty, hold down RB on Xbox as you press the shoot button, and R1 for Playstation. The placed penalty supposedly has more accuracy than the regular driven one, and thus less a chance of missing the target. Other than this, follow the same principles as given for the driven penalty tutorial.
There really isn't much use for the chipped penalty other than to be cheeky. Only try to do this if you are quite sure that your opponent will make he keeper dive one way, as you will look stupid if you try it and it chips up right into the hands of the keeper. To execute a chipped penalty, hold down LB as you press the shoot button on Xbox, and L1 for Playstation.
Believe it or not, the best way to save penalty kicks is not by diving. By moving the right analog stick, you can quickly shuffle your goalkeeper side-to-side across the goal. The concept is the same as for diving, just guess what direction your opponent will shoot. The difference between diving and this method is that he can cover all heights of shot, not one or the other (high or low) as it is for diving. As soon as your opponent has finished charging up his power bar, move your keeper using the right analog stick to where you believe he is going to shoot. If it is going that direction and you did it right, your keeper will save it.
There are only three places your opponent can shoot if you use this; left, right or middle. A 33% rate of success is much better than the roughly 20% offered by the traditional method of diving (or not) and this is not factoring in that sometimes the keeper doesn't save it even though you controlled him to dive the right way.