You should be eligible for " fast track". Ask on plane if they don't offer it.

Yes. You will get fast track on arrival and departure.

That is very welcome news, especially for the security line at departure.

I don't dispute the recommendation (above) to arrive no later than 2 hours before my departure. But I sure hope it doesn't actually take that long!! I get a bit impatient in lines.

If you don't need the 2for1's definitely get your oyster at LHR w/ a 7 day zone 1-2 travelcard and some extra PAYG for the LHR return and trip to HCP if you go there. The window agent will advise you how much PAYG £ you need.

You might find it easier to take the Picadilly line to Hammermith, and change to the District line, exiting at Embankment and walking up Craven Street.

I wonder if the District line from Hammersmith would be a less crowded or more crowded line....?

It isn't the crowd or no crowd. The transfer at Hammersmith is the easiest on the entire system.

You simply exit the train and walk a few feet directly across the platform and board the next west bound district line train.

That sounds ideal. I've now reviewed all these options on the Transport for London website.

We got home yesterday after an unscheduled overnight in Washington DC for The Snowstorm That Never Came.

The Oyster card with one-week Zone 1 and 2 travel card loaded onto it (plus some extra PAYG for trips outside the zone) proved both convenient and cost effective.

The 2 for 1 paper card really wouldn't have helped us. We mostly visited free sites and/or got half price tickets by booking online in the special Feb. deal for historic palaces.

Our only admission was for the Sargent show at the Nat Portrait Gallery. Brilliant show, wonderfully curated. Allow 2 hours minimum.

We had such a good time that we decided to keep the Oyster cards for another trip, perhaps in Oct 2015 or April 2016.

Transferring at Hammersmith was a brilliant suggestion. It took about 10 seconds as the connecting train was already there, with doors open.

Terminal 2, though oppressively vast, with long distances to walk, was very efficient. Immigration (inbound) and security (outbound) were speedy. A much pleasanter experience than Dulles airport, where confusion generally rules.

A high point was the small United/ Air Canada Arrivals lounge in Terminal 2. We had lots of time for our 12:30 rendezvous, so we popped in for a shower and some breakfast.

Courtesy and personal attention rein there. A very agreeable entry into the UK.

I plan to provide a trip report in a few days. Thanks to all for your help.

Make that *reign* not *rein*

terrific. Glad the Oyster, and changing at Hammersmith worked . . . I learned that trick probably 15 years ago on a Fodors thread.