I am a regular visitor to London and have always purchase 1 day travel cards each day (usually im there for 3 days). Are the 1 day travelcards still the best value or shall i look nto an Oyster Card? Ive never used one beofre so not too sure how they work. How much does it deduct from your balance each time you use the underground? Some days we find ourselves hopping on and off trains all day, some days we only use it 2 or 3 times. We are staying at Swissotel the Howard so nearest tube is Temple, but i understand Covent Garden is within easy walking distance.