background.html

<script type="text/javascript">

    var g_currentTab;

    function openAllUrls(info, tab)
    {
        g_currentTab = tab;
        chrome.tabs.sendRequest(tab.id, "openSelectedUrls", openUrls);
    }

    function openUrls(params)
    {
        urls = eliminateDuplicates(params.urls);
        fromUrl = params.fromUrl;

        var baseUrl = fromUrl.replace(/#.+$/, '');

        var skippedAnchors = 0;
        var openedUrls = 0;

        var insertAtIndex = g_currentTab.index + 1;
        var openerTabId = g_currentTab.id;


        for (var i in urls)
        {
            url = urls[i]
            var relativeUrl = url.replace(baseUrl, '');
            if (url.match("^javascript:.*") || relativeUrl.match("^#$"))
            {
                // Ignore links with href of 'javascript:....' or '#'
                continue;
            }
             if (relativeUrl.match("^#"))
             {
                // Don't open links which are #anchors within the current page
                skippedAnchors += 1;
                continue;
             }
            openUrl(url, openerTabId, insertAtIndex++);
            openedUrls += 1;
        }

        if (openedUrls == 0)
        {
            if (skippedAnchors > 0)
            {
                alert('No tabs were opened because all the links selected go to other sections of this page (#anchor links).');
            }
            else
            {
                alert('No links found in selection.');
            }
        }
    }

    function openUrl(url, openerTabId, index)
    {
        if (openerTabId)
        {
            var prop = {
                url: url,
                index: index,
                openerTabId: openerTabId,
                active: false
            }
        }
        else
        {
            var prop = {
                url: url,
                active: false
            }
        }
        chrome.tabs.create(prop);
    }

    function eliminateDuplicates(arr)
    {
        var i, len = arr.length,
            out = [],
            obj = {};

        for (i = 0; i < len; i++) {
            obj[arr[i]] = 0;
        }
        for (i in obj) {
            out.push(i);
        }
        return out;
    }

    chrome.contextMenus.create({
        "title": "Open selected links in new tabs",
        "contexts": ["selection"],
        "onclick": openAllUrls
    });

</script>