blog.linknode.net

// ==UserScript==
// @name           Google Reader with InstaReader
// @namespace      http://linknode.net
// @description    Open feed item with InstaReader in background by pressing 'v'
// @include        http*://www.google.com/reader/view/*
// ==/UserScript==

document.addEventListener('keypress', function(event) {
    if(event.which == 118) { // 118 is 'v'
        if (document.getElementById('current-entry') == null) return; // no current entry

        var link = document.getElementById('current-entry').getElementsByTagName('a').item(0).getAttribute('href');
        var url  = 'http://www.instapaper.com/text?u=' + encodeURIComponent(link);
        event.stopPropagation();
        event.preventDefault();
        GM_openInTab(url);
    }
}, true);

インストールはこちら

https://gist.github.com/raw/825918/5a9f84f2745a062450ec766d213be4fc095b6804/google_reader_with_instareader.user.js