Create random colored squares... marginally useful.

RandomCanvasContent.js

function getRandomInt(min, max) {
    return Math.floor(Math.random() * (max - min + 1)) + min;
}


// Build Canvas
var canvas = document.createElement('canvas'),
    ctx = canvas.getContext('2d'),
    w = canvas.width,
    h = canvas.height,

// Generate Random Rectangle
    ww = getRandomInt(20, w),
    hh = getRandomInt(20, h),
    xx = getRandomInt(0, w/2),
    yy = getRandomInt(0, h/2),
    c = ["blue","yellow", "green", "orange", "purple", "red", "grey", "brown", "white"];

// Render Random Content
ctx.rect(xx, yy, ww, hh);
ctx.fillStyle = c[ getRandomInt (0, c.length - 1)];
ctx.fill();

document.body.appendChild(canvas);