Continuing the minor soccer hijack...(just to warn you all

)
Firstly, the German women beat the American women because the German team is the other main power in women's football, if I remember. Next time around, the USA might win it again. Who knows?
As for the offside rule, it's much simpler than it seems. It's all about keeping players from lurking around near the goal, as pointed out before.
At the moment the ball is played forwards, the assistant referee has to judge whether any attackers are closer to the goal-line than the defenders. The goalkeeper doesn't count for the purposes of this explanation. If the attacking player and the defender are level, that's also fine. The endless debate and argument comes into play when you find out that some idiot put a clause into the rule about 'interfering with play', which means that if you're offside but you don't move or something, play can continue.
I'll try a little pictorial explanation, too.
A1: Player making a pass (attacker)
A2: Player we're looking at to see if he's offside
D1-4: Defenders
1) Player not offside
...............................D1
.....................D2
A1.....................A2
....................D3
........................D4
Although A2 is closer to the goal line that D2 or D3, D1 is closer than him, so he's not offside.
2) Player offside
...............................D1
...............................D2
A1...............................A2
...............................D3
...............................D4
This time, the defence has moved forwards just before A1 passes the ball, and so A2 is caught offside. Flag goes up, and play restarts from the position of the offside player.
The habit of using offside as a major defensive gamble was very popular in the 80's, but it was hellishly boring to watch. The rules were changed so an attacker level with the defence was not flagged offside, and referees were encouraged to give the benefit of the doubt to the attacking team, which livened up the game a lot.
