On Nov 25, 8:24*am, MIG wrote:
Then there are the (rare) trips not entering the UK through Heathrow.

For which Oyster is useless until arrival in London proper. *Except for
arrivals (not direct from the US) into St. Pancras and London City,
where I believe Oyster cards are readily available. *(Or are Oysters not
available at DLR stations?)

Oyster isn't available at DLR stations, unless they are also LU
stations (eg Canning Town).

....except for LCY and Canary Wharf, which have travel centres that
'sell' Oyster cards, as well as having top-up machines:
http://www.tfl.gov.uk/tickets/oysteronline/4700.aspx

--
John Band
john at johnband dot org
www.johnband.org