I have been sent a link by my sister regarding an up-and coming scheme in the UK which with enough members will allow between 5-10p on a litre of petrol.
Basically the scheme allows members to register, the scheme them "buys" petrol in bulk at a discount, it then re-sells the petrol to you via the pipeline card.
They are forcasting that the actuall cards will be issued around April/May.
The more members, then the bigger the discount could be.
http://www.pipelinecard.org/