I finally found an article that explains the meaning of our prayer beads, or juzu. Yippee!!
It is taken from here.
[O]ur prayer beads consist of two long strands joined at either end with two large beads. Hanging from the outside of these large beads are two shorter strands on one side, and three on the other. They are strung with white braided cords with white pompom tassels at the end. These sets of two and three strands are equidistant and opposite from each other. The two large beads are called the father and mother beads. Both of them represent the Buddha. Between the father and mother beads are 108 beads of a smaller size. These beads represent earthly desires. There are also four smaller beads. They are opposite each other, two being seven beads away from the end with two strands, and the other two are fourteen beads beyond the first two. These four small beads represent the four leaders of the Bodhisattvas of the Earth — Jogyo (Superior Practice), Muhengyo (Boundless Practice), Jougyo (Pure Practice), and Anryugyo (Unwavering Practice) — and also indicate the four virtues of the Buddha’s life. These are eternity, tranquility, true self, and purity. Directly under the father bead, which is at the end with two tassels, is a smaller bead. This represents the essential nature of the Law, the eternal, absolute truth.
This article is very nice, but I still prefer the way my father explained the meaning of the prayer beads to me when I was a child.
The two strands on one side represent the legs, the three on the other the head and arms of a stylised human figure.
When you twist the braided cords in the middle before you wear them to pray, you essentially create the shape of an eight, symbol of the infinite.
The ten fingers of your hands represent the ten worlds: Hell, Hunger, Animality, Anger, Humanity, Rapture, Study, Realisation, Bodhisattva, Buddhahood (I will write more about them in another entry).
As you wear it on your hands, and you join your hands in prayer, you are basically symbolising the idea that your infinite life, which mutually possesses the ten worlds, is entirely your responsibility.