I know a great trip, We can go on a great Boat Trip on the Thames, Starts Westminster Pier, can hop-on-and hop-off along the Thames (as many times as we like), at most of the sites ALL DAY LONG FOR £10, chat, socialise, make friends, couple of Hours at Greenwich market, shops & Restaurants, bookshops or Antiques, take boat back, jump off at London Eye, and get boat back to Westminster, (everyone is free to do as they wish, or just stay on the boat seeing the sites & chatting, the river is so relaxing) TICKET INCLUDES USE OF BOAT TRIPS ALL DAY LONG 10am-7;30pm approx. Boat has Restaurant & Bar, can cruise on the outside Deck (with nice drink or tea) with siteseeing, or stay inside, Tea, Coffee, drinks, eats available all day. City Cruises River Red Rover Ticket £10 each, tickets can be bought at Westminster Pier on day or before.
Great Trip, I have done it 4 times with friends & partner, still Love it!!
Easily One of Londons 5*star trips (day out) . At a reasonable price for an all day boat trip.

Greenwich & Docklands International festival 2010, 24th July- 4th July, www.festival.org

"an event whose annual contribution to the happiness of the people of London is unrivalled" The Guardian

The amphibious DUKW was used in WW2 and takes one on a tour of central London and then onto the Thames.

The Anish Kapoor exhibition opens at the Royal Academy on 26 Sep, and I want to be one of the first people through the door! I love his sculpture.
http://www.royalacademy.org.uk/exhibitions/anish-kapoor/

This has many cartoons from newspapers etc over the years plus political cartoons and Hogarth cartoons and some satirical ones & some done in the style of Hogarth. It is not expensive and would probably so would probably do a good discount. It's near the British Museum so easy for people to find and near cafes and pubs for afterwards.

This museum has every type of cartoon from very funny and vulgar through to political and satirical. It also includes some cartoons by Hogarth and modern works using his techniques. Entrance is either free or very cheap, I forget which, and it is near the British Museum so easy to find. Also there's a cheap chinese restraunt nearby and, if you prefer, a large Japanese restraunt also.