your_location_bookmarks.user.js

// ==UserScript==
// @name           Your Location Bookmarks
// @namespace      kurain.net
// @include        http://b.hatena.ne.jp/*
// ==/UserScript==
(function () {

    var KEY = 'ABQIAAAAesrOSnfHiupcC1SX4HlcpxS4Ub5LNodPnSvUeVQvSorjE2hlyhSzO7n6dOEDwvDXs9DXsJW21wCMkQ';

    var prefectures = {
        "北海道" : "HOKKAIDO",
        "青森県"   : "AOMORI",
        "岩手県"   : "IWATE",
        "宮城県"   : "MIYAGI",
        "秋田県"   : "AKITA",
        "山形県"   : "YAMAGATA",
        "福島県"   : "FUKUSHIMA",
        "茨城県"   : "IBARAKI",
        "栃木県"   : "TOCHIGI",
        "群馬県"   : "GUNMA",
        "埼玉県"   : "SAITAMA",
        "千葉県"   : "CHIBA",
        "東京都"   : "TOKYO",
        "神奈川県" : "KANAGAWA",
        "新潟県"   : "NIIGATA",
        "富山県"   : "TOYAMA",
        "石川県"   : "ISHIKAWA",
        "福井県"   : "FUKUI",
        "山梨県"   : "YAMANASHI",
        "長野県"   : "NAGANO",
        "岐阜県"   : "GIFU",
        "静岡県"   : "SHIZUOKA",
        "愛知県"   : "AICHI",
        "三重県"   : "MIE",
        "滋賀県"   : "SHIGA",
        "京都府"   : "KYOTO",
        "大阪府"   : "OSAKA",
        "兵庫県"   : "HYOGO",
        "奈良県"   : "NARA",
        "和歌山県" : "WAKAYAMA",
        "鳥取県"   : "TOTTORI",
        "島根県"   : "SHIMANE",
        "岡山県"   : "OKAYAMA",
        "広島県"   : "HIROSHIMA",
        "山口県"   : "YAMAGUCHI",
        "徳島県"   : "TOKUSHIMA",
        "香川県"   : "KAGAWA",
        "愛媛県"   : "EHIME",
        "高知県"   : "KOCHI",
        "福岡県"   : "FUKUOKA",
        "佐賀県"   : "SAGA",
        "長崎県"   : "NAGASAKI",
        "熊本県"   : "KUMAMOTO",
        "大分県"   : "OITA",
        "宮崎県"   : "MIYAZAKI",
        "鹿児島県" : "KAGOSHIMA",
        "沖縄県"   : "OKINAWA"
    };


    function jumpLink( dist ) {
        window.location.href = dist;
    }
    
    function getName ( json ) {
        var data = eval(json);
        var kanjiName = data.result.prefecture.pname;
        var ucName = prefectures[kanjiName];
        var locationPage = 'http://b.hatena.ne.jp/location/' + ucName.toLowerCase();
        jumpLink( locationPage )
    }
    
    function getPrefecture (lat, lng) {
        var url = 'http://www.finds.jp/ws/rgeocode.php?lat=' + lat + '&lon=' + lng + '&jsonp=getName';
        GM_xmlhttpRequest({
            method:  "GET", 
            url:     url,
            onload:  function(x){eval(x.responseText)}
        });
    }

    function getLocation (e) {
        e.preventDefault();
        navigator.geolocation.getCurrentPosition(function(position) {
            getPrefecture(position.coords.latitude, position.coords.longitude);  
        });
    }

    function drawLocationLink () {
        var navLink = document.createElement('li');
        var anchor  = document.createElement('a');
        
        anchor.setAttribute('id',   'location-page-link' );
        anchor.setAttribute('href', 'location')
        anchor.appendChild( document.createTextNode('地域') );
        
        anchor.addEventListener('click', getLocation, true);
        
        navLink.appendChild(anchor);
        var target = document.getElementById('header-navigation');
        var posTarget = target.childNodes[2];
        target.insertBefore(navLink, posTarget);
    };
    
    if (navigator.geolocation) {
        drawLocationLink();
    }
    
})();