I was in the Horsebridge art and community centre in Whitstable, and an artist was asking visitors to choose a coloured board, and arrange different coloured bottle caps on the board until they found the colours pleasing - at which point, a note was taken of the positioning, and sometime soon, everyone's individual pieces will be combined into one final piece of art work - i'm not sure when, though, if you want to find out more, the Horsebridge website might be able to help.