Small jQuery plugin which generates Piet Mondrian-style canvases and places it as a background on selected elements.
Only really tested in modern (non-IE) browsers on divs and the body (see it in use at http://breakfastdinnertea.co.uk).
Customisable settings:
$.fn.mondrian.defaults = {
foreground: '#000',
background: '#fff',
lineWidth: 3,
lineCap: 'square',
linesX: 4,
linesY: 6,
colors: ['red','green','blue']
};