I subscribe to an on-line travel Super Savings website. The site e-mails deals weekly and last week I was made aware that a non-stop from my closest airport to the U.K. was available (NOTE: This never happens at an affordable rate and when it does it's always from a far off airport).
Included in the round trip ticket deal was 1, three day, "The London Pass" per ticket. You simply can't go wrong when they just GIVE you the ticket.
So, if you are craving a U.K. trip with London as part of your scheduled exploratory ventures, I say be patient and watch for announcements from on-line travel/airline sites. Sooner or later the 2 for 1 deal will drop again to 2 for 0. Travel Safe & Be Smart. NOTE: Special thanks to Rick: My local library stocks your books and DVDs. Let me get back to Rick Steve's London, Rick Steve's Best Of Europe, Rick Steve's Best European City Walks and Museums and Rick Steve's Europe Through The Back Door.