Make stuff hover around like balloons or something, assumes elements are already positioned absolute with top and left/right values.

balloons.jquery.js

;(function($){

  $.fn.balloons = function(options) {
    var balloons = this,
        cssAnim = Modernizr && Modernizr.cssanimations,
        opts = $.extend({}, $.fn.balloons.defaults, options),
        /* Helper function to return random range */
        getRand = function(min, max) {
          return Math.floor(Math.random() * (min-max+1)) + max;
        },
        /* Main movement function */
        moveBalloons = function() {
          var ele = arguments[0] ? arguments[0] : $(this);
              $w = $(window),
              winh = $w.height(),
              winw = $w.width();
          /* Make sure we got a jQuery collection */
          ele = ele instanceof jQuery ? ele : $(ele);
          /* Move each element separately */
          ele.each(function(i, el) {
            var balloon = $(el),
                bwidth = balloon.width(),
                bheight = balloon.height(),
                lpos = parseInt(balloon.css(opts.side)),
                tpos = parseInt(balloon.css('top')),
                ldis = getRand(-opts.speed, opts.speed),
                tdis = getRand(-opts.speed, opts.speed),
                lnew = lpos + ldis,
                tnew = tpos + tdis,
                pos = {},
                rmost = opts.side == 'left' ? lnew + bwidth : lnew,
                duration = getRand(opts.min, opts.max);
            pos[opts.side] = (lnew > 0 && rmost < winw) ? lnew : lpos;
            pos.top = (tnew > 0 && (tnew + bheight) < winh) ? tnew : tpos;
            if (cssAnim) {
              pos['-webkit-transition-duration'] = pos['-moz-transition-duration'] = pos['transition-duration'] = duration + 'ms';
              balloon.css(pos);
              setTimeout(moveBalloons, duration, [balloon]);
            }
            else {
              balloon.animate(pos, duration, 'linear', moveBalloons);
            }
          });
        };
    if (cssAnim) {
      this.css({
        '-webkit-transition-property': 'top, ' + opts.side,
        '-moz-transition-property': 'top, ' + opts.side,
        'transition-property': 'top, ' + opts.side,
        '-webkit-transition-timing-function': opts.easing,
        '-moz-transition-timing-function': opts.easing,
        'transition-timing-function': opts.easing
      });
    }
    /* Initiate */
    moveBalloons(this);
    /* Return collection */
    return this;
  };

  $.fn.balloons.defaults = {
    speed: 150, /* max change in px for a single interval */
    min: 3000, /* min delay in ms */
    max: 5000, /* max delay in ms */
    side: 'left', /* attribute to manipulate, left or right */
    easing: 'linear' /* easing to use for the animations */
  }

})(jQuery);

example on http://jsbin.com/balloons/8