I'm afraid that the graphics card is not really suitable for gaming. You could probably get away with some light gaming on it e.g. lower the resolution and turn off most of the effects.
My laptop uses a Nvidia 7600 graphics chipset and to be honest even though it's better then the 7400, it still struggles and I am shortly looking to upgrade to one of the newer ones based on the 8800 range that is shortly to be announced for laptops.
The trouble really is that high powered graphics use lots of power and really heat up, they therefore tend to be available in the 17"+ screen models as they have more room inside to keep things cool.
Keep in mind the maximum screen resolution of any laptop you buy as it's no good paying a fortune for a machine with a whizzy graphics card if your max screen resolution is low as you are paying for something you will get no benefit from.