Marker Tooltips Outside the Map

Show tooltip contents outside of the map
<!DOCTYPE html>
<html>
<head>
<meta charset=utf-8 />
<title>Marker Tooltips Outside the Map</title>
  <meta name='viewport' content='width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no' />
  <script src='//api.tiles.mapbox.com/mapbox.js/v1.4.0/mapbox.js'></script>
  <link href='//api.tiles.mapbox.com/mapbox.js/v1.4.0/mapbox.css' rel='stylesheet' />
  <!--[if lte IE 8]>
    <link href='//api.tiles.mapbox.com/mapbox.js/v1.4.0/mapbox.ie.css' rel='stylesheet'>
  <![endif]-->
  <style>
    body { margin:0; padding:0; }
    #map { position:absolute; top:0; bottom:0; width:100%; }
  </style>
</head>
<body>
<style>
  #map { position:absolute; top:0; bottom:0; right:300px; left:0; }
  #info {
      position:absolute; top: 0; right: 0;
      bottom: 0; width: 260px; background:#333; color: #fff;
      padding:20px;
  }
  h1 { margin-top:0; }
</style>


<div id='map'></div>
<div id='info'></div>

<script>
var map = L.mapbox.map('map', 'examples.map-20v6611k')
    .setView([37.9, -77], 6);

var geoJson = [
    {
        type: 'Feature',
        geometry: {
            type: 'Point',
            coordinates: [-77, 37.9]
        },
        properties: {
            title: 'Marker One',
            description: '<strong>Wow</strong>, this tooltip is breaking all the rules.',
            // http://mapbox.com/developers/simplestyle/
            'marker-color': '#CC0033'
        }
    },
    {
        type: 'Feature',
        geometry: {
            type: 'Point',
            coordinates: [-78, 36.5]
        },
        properties: {
            title: 'Marker Two',
            description: 'Another marker, including <a href="http://mapbox.com">a link</a>.',
            'marker-color': '#0099ff'
        }
    }
];

map.markerLayer.setGeoJSON(geoJson);

// Listen for individual marker clicks
map.markerLayer.on('click',function(e) {
    e.layer.unbindPopup();

    var feature = e.layer.feature;
    var info = '<h1>' + feature.properties.title + '</h1>' +
               '<p>' + feature.properties.description + '</p>';

    document.getElementById('info').innerHTML = info;
});

// Clear the tooltip when map is clicked
map.on('click',function(e){
    document.getElementById('info').innerHTML = '';
});

</script>
The code and documentation to mapbox.js is hosted on GitHub where you can contribute changes and improvements.