Originally Posted by chaneytexas
You'll be fine with a credit card for everything except for the Hotel Hoppa Bus, which will take you to the Renaissance... I don't believe they take credit cards.
You can't use a credit card on the bus, but you can use a card in the machine at the bus stop at LHR (certainly at T2, which is normally the place where I'm travelling from). You can also usually get your hotel to add the return ticket to your folio and have them issue you it.