Quote: Horatio Yed "Personally i wouldn't get ripped off by paying cash every time i travel, You get Oyster Cards from underground stations, £5 refundable deposit and then add what ever money you think you'll need, if at the end of your stay you hand your card in to the station with a receipt you'll get your fiver back plus what ever money you had on the card.
It saves you loads of money.'"
Cheers for the tip fella, just ordered myself one online.