Add shortcut key T for Reblog on Tumblr Dashboard.

reblogable.user.js

// ==UserScript==
// @id             Reblogable
// @name           Reblogable
// @namespace      http://syoichi.tumblr.com/
// @version        0.0.5
// @description    Add shortcut key T for Reblog on Tumblr Dashboard.
// @include        http://www.tumblr.com/dashboard*
// @include        http://www.tumblr.com/show/*
// @include        http://www.tumblr.com/likes*
// @include        http://www.tumblr.com/liked/by/*
// @include        http://www.tumblr.com/tagged/*
// @include        http://www.tumblr.com/blog/*
// @exclude        http://www.tumblr.com/dashboard/iframe*
// @run-at         document-end
// ==/UserScript==

/* User Script info
license: Public Domain
confirmed:
    Windows 7 Home Premium SP1 64bit:
        Firefox 16.0.1(Scriptish 0.1.8)
        Google Chrome 22.0.1229.94
        Opera 12.02 64bit
*/

/*jslint browser: true, maxlen: 80*/
// Edition 2012-10-03

(function executeReblogable(win, doc) {
    'use strict';

    var KEY, KEY_CODE, POST_MARGIN_TOP;

    if (!doc.querySelector('li[id^="post_"]')) {
        return;
    }

    KEY = 't'; // or r, h, and so on.
    KEY_CODE = KEY.toUpperCase().charCodeAt();
    POST_MARGIN_TOP = 7;

    win.addEventListener('keydown', function reblogable(evt) {
        var isKey, modKey, post, nextPost, reblogButton, altClick;

        isKey = evt.keyCode === KEY_CODE;

        if (!isKey) {
            return;
        }

        modKey = evt.altKey || evt.ctrlKey || evt.shiftKey || evt.metaKey;

        if (modKey || evt.target.tagName !== 'BODY') {
            return;
        }

        post = doc.elementFromPoint(win.innerWidth / 2, POST_MARGIN_TOP + 1);

        if (!post) {
            return;
        }

        reblogButton = post.querySelector('.reblog_button');

        if (!reblogButton) {
            return;
        }

        evt.stopPropagation();

        nextPost = doc.querySelector('#' + post.id + ' ~ .post');

        if (nextPost) {
            win.scrollBy(
                0,
                nextPost.offsetTop - win.pageYOffset - POST_MARGIN_TOP
            );
        }

        altClick = doc.createEvent('MouseEvent');

        altClick.initMouseEvent('click',
            true, true, win, 1, 0, 0, 0, 0, false, true, false, false, 0, null);
        reblogButton.dispatchEvent(altClick);
    }, true);
}(window, document));