I was last in London in August 2006. I'm returning this week, arriving
Thursday morning at Heathrow T3.

Will my Oyster card still work?

And if I do need a new one, is the £3 deposit still waived if I buy a 7-
day Travelcard when I obtain the card? And how far in advance can I buy
a Travelcard? I might not want it to start up right away.

Thanks.
--
David of Broadway
New York, NY, USA