Apparently since 1912 each Olympic host city has commissioned posters
to celebrate hosting the Games and since the first Paralympic
games were held at Stoke Mandeville, posters have also been commissioned
for the Paralympic games.
Art of the Underground said "These official posters are now themselves a
special celebration of the meeting of art and sport over the last 100
years. The London Organising Committee of the Olympic and Paralympic
Games (LOCOG) has commissioned twelve of the UK’s leading artists to
create images to celebrate London hosting the 2012 Games, six for the
Olympic Games and six for the Paralympic Games."
"The artists were encouraged to celebrate the Games coming to London and
to look at the values of the Olympic and Paralympic games. Each image is
a distinct interpretation of either the Olympic or Paralympic Games by
the individual artists and the diversity of the series demonstrates the
extraordinary creative talent that exists within the UK".
The posters are from artists Martin Creed, Tracey Emin, (who is also penned the artwork for the current Tube map covers), Gary Hume, Sarah Morris, Bob and Roberta Smith, Anthea Hamilton, Howard Hodgkin, Chris Ofili, Bridget Riley, Rachel Whiteread, Fiona Banner and Michael Craig-Martin.
The images are also on display at Tate Britain during the summer as
part of the London 2012 Festival and are available to buy as posters or
limited edition prints.