The minimap provides you with a new way to visualize your site.

extensions.js

/** pQuery! LOL **/
Object.extend($, Prototype);
Object.extend($, Object);


/**
 * Returns window dimensions and scroll positions
 * @author Firejune<to@firejune.com>
 * @license MIT
 */

Object.extend(Position, {
  getPageSize: function() {
    var doc = window.scrollMaxX ?
      {w: window.innerWidth  + window.scrollMaxX, h: window.innerHeight + window.scrollMaxY} :
      {w: document.body.scrollWidth, h: document.body.scrollHeight};

    var win = self.innerHeight ? 
      {w: self.innerWidth, h: self.innerHeight} : // IE
      document.documentElement && document.documentElement.clientHeight ?
        {w: document.documentElement.clientWidth, h: document.documentElement.clientHeight} : {w: 0, h: 0};

    // for small pages with total size less then size of the viewport
    doc = {w: Math.max(win.w, doc.w), h: Math.max(win.h, doc.h)};

    return { page: { width: doc.w, height: doc.h }, window: { width: win.w, height: win.h } };
  },
  scrollX: function() {
    return (window.scrollX || window.pageXOffset || document.documentElement.scrollLeft || document.body.scrollLeft || 0);
  },
  scrollY: function() {
    return (window.scrollY || window.pageYOffset || document.documentElement.scrollTop || document.body.scrollTop || 0);
  }
});


/**
 * Position based scrollTo effect
 * @author Firejune<to@firejune.com>
 * @license MIT
 */

Effect.Scroll = Class.create(Effect.Base, {
  initialize: function(top, left) {
    
    var args = $A(arguments)
      , options = typeof args.last() == "object" ? args.last() : {};

    this.scroll = {
        left: left || 0
      , top: top
    };

    this.start(options);
  },
  setup: function() {
    this.scrollX = Position.scrollX();
    this.scrollY = Position.scrollY();

    var getSize = Position.getPageSize();
    var max = getSize.page.height - getSize.window.height;
    if (this.options.offset) this.scrollY += this.options.offset;
    if (this.options.offset) this.scrollY += this.options.offset;

    this.delta = {
        x: (this.scroll.left > max ? max : this.scroll.left) - this.scrollX
      , y: (this.scroll.top > max ? max : this.scroll.top) - this.scrollY
    }
  },
  update: function(position) {
    scrollTo(
        (this.scrollX + position * this.delta.x).round()
      , (this.scrollY + position * this.delta.y).round());
  }
});

minimap.js

/*!
 * minimap 0.1 (http://firejune.com/1704)
 * based on fracs (http://larsjung.de/fracs)
 * 
 * provided under the terms of the MIT License
 *
 * requires: 
 * - prototype.js prototype 1.6.0+ (http://www.prototypejs.org)
 * - scriptaculous 1.8.0+ (http://script.aculo.us)
 * - extensions.js (http://firejune.com)
 */

var Minimap = (function(doc, win) {

  /*
   * Options.
   */

  var $options = {
        crop: false
      , invert: false
      , width: 100
      , height: 400
      , duration: 0.2
      , focusWidth: 0.5
      , focusHeight: 0.5
      , transition: Effect.Transitions.flicker
      , styles: [
          {selector: 'header,footer,section,article', fillStyle: 'rgb(230,230,230)'}
        , {selector: 'h1', fillStyle: 'rgb(240,140,060)'}
        , {selector: 'h2', fillStyle: 'rgb(200,100,100)'}
        , {selector: 'h3', fillStyle: 'rgb(100,200,100)'}
        , {selector: 'h4', fillStyle: 'rgb(100,100,200)'}
      ]
      , viewport: {fillStyle: 'rgba(228,77,38,0.3)'}
      , drag: {fillStyle: 'rgba(228,77,38,0.6)'}
    }
    , $canvas
    , $context
    , $drag;


  /*
   * Class.
   */

  return function(options) {
    $options = $.extend($options, options);
    $canvas = new Element('canvas', {
        id: 'outline'
      , width: $options.width
      , height: $options.height
    });

    if (!($canvas instanceof HTMLElement)
       || $canvas.nodeName.toLowerCase() !== 'canvas')
      return console.error('Your browser does not support Canvas');

    doc.body.insert($canvas);

    this.draw = draw;
    this.scroll = scroll;

    $context = $canvas.getContext('2d');
    $canvas.setStyle('cursor: pointer').observe('mousedown', function(event) {
      event.stop();
      $drag = true;
      $canvas.setStyle('cursor: crosshair');
      doc.body.setStyle('cursor: crosshair');
      Event.observe(win, 'mousemove', scroll);
    });

    Event.observe(win, 'mouseup', function(event) {
      event.stop();
      $canvas.setStyle('cursor: pointer');
      doc.body.setStyle('cursor: auto');
      Event.stopObserving(win, 'mousemove', scroll);
      $drag = false;
      draw();
      event.element() == $canvas && scroll(event);
    });

    $canvas.onselectstart = function() {
      return false;
    };

    Event.observe(win, 'load', draw);
    Event.observe(win, 'resize', draw);
    Event.observe(win, 'scroll', draw);

    draw();

    console.info('Initialized minimap.');
  };


  /*
   * Core.
   */

  function scroll(event) {
    var r = rect($canvas)
      , x = event.clientX - r.left
      , y = event.clientY - r.top;

    scrollTo(
        x / draw.scale - draw.win.width * $options.focusWidth
      , y / draw.scale - draw.win.height * $options.focusHeight
      , event.type == 'mousemove' ? 0 : $options.duration);
  }

  function scrollTo(left, top, duration) {
    scroll.ani && scroll.ani.state == 'running' && scroll.ani.cancel();
    scroll.ani = new Effect.Scroll(top, left, {
        fps: 100
      , duration: duration
      , transition: $options.transition
    });
  }

  function draw() {
    var vp = viewport()
      , scaleX = $options.width / vp.doc.width
      , scaleY = $options.height / vp.doc.height;

    if ($options.crop) {
      $canvas.width = vp.doc.width * draw.scale;
      $canvas.height = vp.doc.height * draw.scale;
    }

    $context.clearRect(0, 0, $canvas.width, $canvas.height);
    $context.scale(draw.scale, draw.scale);

    $.extend(draw, {
        scale: scaleX < scaleY ? scaleX : scaleY
      , doc: vp.doc
      , win: vp.win
    });

    applyStyles($context);
    drawViewport();

    $context.scale(1 / draw.scale, 1 / draw.scale);
  }

  function applyStyles(context) {
    for (idx in $options.styles) {
      var style = $.extend({
          strokeWidth: 'auto'
        , strokeStyle: 'auto'
        , fillStyle: 'auto'
      }, $options.styles[idx]);

      $$(style.selector).each(function(el) {
        el.visible() && drawElement(
            context
          , el
          , style.strokeWidth
          , style.strokeStyle
          , style.fillStyle);
      });
    }
  }

  function drawElement(context, element, strokeWidth, strokeStyle, fillStyle) {
    var position = rect(element);

    strokeWidth = strokeWidth == 'auto' ?
      parseInt(element.getStyle('border-width')) || '' : strokeWidth;
    strokeStyle = strokeStyle == 'auto' ?
      element.getStyle('border-color') : strokeStyle;
    fillStyle = fillStyle == 'auto' ?
      element.getStyle('background-color') : fillStyle;

    drawRect(context, position, strokeWidth, strokeStyle, fillStyle);        
  }

  function drawViewport() {
    if ($drag === true && $options.drag !== undefined) {
      var storkeWidth = $options.drag.storkeWidth;
      var strokeStyle = $options.drag.strokeStyle;
      var fillStyle = $options.drag.fillStyle;
    } else {
      var storkeWidth = $options.viewport.storkeWidth;
      var strokeStyle = $options.viewport.strokeStyle;
      var fillStyle = $options.viewport.fillStyle;
    }

    drawRect(
        $context
      , draw.win
      , storkeWidth
      , strokeStyle
      , fillStyle
      , $options.invert);
  }

  function drawRect(context, rect, lineWidth, strokeStyle, fillStyle, invert) {
    invert = invert || false;

    lineWidth = lineWidth > 0.2 / draw.scale ? lineWidth : 0.2 / draw.scale;

    if (invert === false) {
      context.beginPath();
      context.rect(rect.left, rect.top, rect.width, rect.height);
      context.fillStyle = fillStyle;
      context.fill();

      context.lineWidth = lineWidth;
      context.strokeStyle = strokeStyle;
      context.stroke();
    } else {
      context.beginPath();
      context.rect(0, 0, draw.doc.width, rect.top);
      context.rect(0, rect.top, rect.left, rect.height);
      context.rect(rect.right, rect.top, draw.doc.right - rect.right, rect.height);
      context.rect(0, rect.bottom, draw.doc.width, draw.doc.bottom - rect.bottom);
      context.fillStyle = fillStyle;
      context.fill();

      context.beginPath();
      context.rect(rect.left, rect.top, rect.width, rect.height);
      context.lineWidth = lineWidth;
      context.strokeStyle = strokeStyle;
      context.stroke();
    }
  }

  function viewport() {
    var size = Position.getPageSize()
      , left = Position.scrollX()
      , top = Position.scrollY();

    return {
        win: new Rect(left, top, size.window.width, size.window.height)
      , doc: new Rect(0, 0, size.page.width, size.page.height)
    };
  }

  function rect(element) {
    var dimensions = element.getDimensions()
      , offset = element.cumulativeOffset();

    return new Rect(offset.left, offset.top, dimensions.width, dimensions.height);
  }

  function Rect(left, top, width, height) {
    this.left = left.round();
    this.top = top.round();
    this.width = width.round();
    this.height = height.round();
    this.right = this.left + this.width;
    this.bottom = this.top + this.height;
  }

})(document, window);