jquery.noiseBackground.js

$.fn.noiseBackground = function (alpha) {
    alpha = alpha || 0.2;
    function generateNoise (alpha) {
        var canvas = document.createElement('canvas');
        if ( !!!canvas.getContext) {
            return false;
        }

        var ctx = canvas.getContext('2d'),
            x,y,
            r,g,b,
            a= alpha;

            canvas.width = 100;
            canvas.height = 100;

        for(x = 0; x< canvas.width; x++){
            for(y = 0; y< canvas.height; y++){
                r = Math.floor(Math.random() * 255);
                g = Math.floor(Math.random() * 255);
                b = Math.floor(Math.random() * 255);
                ctx.fillStyle = 'rgba('+r+','+g+','+b+','+a+')';
                ctx.fillRect(x,y,1,1);
            }
        }
        return canvas.toDataURL("image/png");
    }

    return $(this).css('backgroundImage',"url("+generateNoise(alpha)+')');
};//END fn.noiseBackground