From the Creative Review Blog in the UK : "The coin is the first in a series of four to be launched annually from now until 2012. On the reverse, it features the number three to signify three years until the start of the Olympic and Paralympic Games, alongside images of swimmers racing to the finish line, while the framework border is a reference to the new Olympic stadium as seen from above. [Link]
From Coin News: "... The reverse or tails side of the coin features a running track, symbolizing the Olympic Games, and was created by Royal Mint engraver Thomas T. Docherty. Within the track is the 1908 anniversary date and circling the track itself are the words, "LONDON OLYMPIC CENTENARY".
The coin also has an incuse edge inscription, "THE 4TH OLYMPIAD LONDON". [Link]
The United States could never do something like this. We have some of the best designers in the world but the we have ugliest money in existence. You should see these quarters they have been minting here lately that are suppose to represent what is great about each state. I had this one quarter in my pocket today from Kansas featuring a warthog on the back of it but I wouldn't spend it till I was sure. It turns out it was a buffalo.