Another option...When we cruised out of Harwich we took SilverFleet car service from our Paddington Hilton hotel and back. DH wasn't too sure about the train because of our luggage and his back & knees. It was 98 pounds for the 2 of us r/t and we stopped for water/soda and were very comfortable and met fellow cruisers. If you google them, you can emial from the website. We did it all by email. We also used them to get to Southampton for our Transatlantic. Tony Hayter, owner, met us at Heathrow and drove us in pouring rain. It was an experience.
I agree about the Capital One. We have used it for over 5 years now and just bumped up the the Venture. It is $59/year but that's the card we use for miles so it will be worth it.
We didn't see the changing of the guard, it was every other day but we saw the changing of the calvary and had a front row seat. Also loved the Buckingham Palace tour.
Teresa and Larry
#36-Carnival Splendor 9/16/12
7 night Mexican Riviera
#37-Allure of the Seas 11/11/12
7 night Eastern Caribbean
#38-Celebrity Solstice 4/8/13
17 night Tahiti -- Sydney-Honolulu
40th Anniversary Celebration
270 days at see; soon to be 302