Okay, I get the Big Ben clock tower.
Houses of Parliament (of which Big Ben is part), 30 St Mary Axe (commonly known as the Gherkin, after a type of pickled cucumber), St. Paul’s Cathedral, Nelson’s Column (which is not actually in that part of London), I think that’s the Tower of London, and Tower Bridge. I don’t know if the smaller buildings in between are depictions of anything famous.
[edit] Maybe it’s St. Paul’s column, not Nelson’s.
Okay, cool, thanks! 
(Ahem, we know what pickles are in America.) 
I heard on the news that you guys are behind schedule! Hurry! The athletes are arriving already! Everything starts IN A WEEK! :eek:
Oh sorry, I thought “gherkin” was a Britishism.
per Isaac Asimov in the USA:
There once was a fellow name Perkin,
Who was alway jerkin’ his gherkin,
His mother said “Perkin!
Stop jerkin’ your gherkin!
Your gherkin’s for firkin, not jerkin’.”
Agree with the answer above -
Houses of Parliament
Big Ben
The Gherkin (I think)
St Paul’s Cathedral
Nelson’s Column
Tower of London
Tower Bridge
The middle bit is out of order for some reason - going from West to East, the Gherkin/St Pauls/Nelson’s Column order should be reversed. I’m surprised they haven’t put the Shard or the London Eye in there too…
Incidentally nothing is really “behind schedule” - the problems have been with the Olympics security contractor G4S leaving its security operation massively understaffed, meaning the police and army have had to be drafted in to provide cover. There’s also been transport issues but they’ve been fairly minor (one of the bus drivers who picked up one of the American teams didn’t know the route to the athlete’s village, so it took them 4 hours to drive about 25 miles, which they weren’t too happy about!).
Am I imagining things in seeing the razor building in that too, as one of the tiny buildings? Or it could be a coincidence.