I tried a couple of american recipes recently, and I have to say: the cups system of measuring is so much better than metric for cookery.

Basically, rather than saying 125g or 50 ml or whatever, the recipes say 1/2 cup, or 3/4 cup etc.. Once you've seen what a 'cup' looks like, you can easily visualize how much of each ingredient you need without having to weigh or measure it out.