Here's an example of a prepaid FlexGo card used in Microsoft's early trial in Brazil.
A screenshot of a PC using Microsoft's FlexGo pay-as-you-go technology. A window in the upper right hand corner shows the amount of time already paid for. Users can add more time with a prepaid card.
Transmeta says its new chip and platform support FlexGo at the hardware level. They will also be present in power-efficient desktops that run on batteries for areas without sustained electricity.