背景いっぱいにドット

gistfile1.js

$(function () {
    var dotSize = 3;
    var dotColor = "#abc";
    var canvas = $("<canvas/>").attr({
        width: dotSize * 2,
        height: dotSize * 2
    })[0];
    var ctx = canvas.getContext('2d');
    ctx.fillStyle = dotColor;
    ctx.beginPath();
    ctx.fillRect(0, 0, dotSize, dotSize);
    ctx.fillRect(dotSize, dotSize, dotSize, dotSize);

    $('body').css({
        'background-image': "url(" + canvas.toDataURL("image/png") + ")"
    });
});