Microsoft markets a prepaid credit card to German teenagers (14 years and older) to be able to sign-up for the Xbox Live gaming service.

In Germany there a still lots of people not owning a credit card. This is one of the reasons online shopping is not developing as fast as in the US for instance.
Now German parents can get their kids a prepaid credit card, if the kids are able to convince them. This might be especially difficult if the parents do not have a credit card themselves.
The credit card terms are not bad. There are no yearly fees, 2% interest on the prepaid balance and the card works like a normal Visa card.
More details on Xbox site (German). See also Heise.de (German).
Xbox Live is one of Microsoft's biggest arguements for the Xbox and it will be a huge driver for the Xbox 360. Sony is way behind here.