Enhance Yahoo! Mail: In Yahoo! Mail, opens the download iframe in a new window so that the attachment can be opened if the file type is associated with the Opera browser.

Enhance Yahoo Mail 1.00.js

// ==UserScript==
// @name Enhance Yahoo! Mail
// @version 1.00
// @description In Yahoo! Mail, opens the download iframe in a new window so that the attachment can be opened if the file type is associated with the Opera browser.
// @author XP1 (https://github.com/XP1/)
// @namespace https://gist.github.com/1126767/
// @include http*://mail.yahoo.*/*
// @include http*://*.mail.yahoo.*/*
// @include http*://mail.yimg.*/*
// @include http*://*.mail.yimg.*/*
// @include http*://yahooapis.*/*
// @include http*://*.yahooapis.*/*
// ==/UserScript==

/*jslint browser: true, vars: true, white: true, maxerr: 50, indent: 4 */
(function (topWindow)
{
    "use strict";

    if (window.self !== topWindow)
    {
        return;
    }

    function disableDownloadIframe()
    {
        topWindow.addEventListener("DOMNodeInserted", function (event)
        {
            var sourceElement = event.srcElement;
            if (sourceElement.tagName.toLowerCase() === "iframe" && sourceElement.hasAttribute("id") && sourceElement.getAttribute("id").indexOf("#dlFrame") !== -1)
            {
                var downloadLink = sourceElement.getAttribute("src");
                sourceElement.parentNode.removeChild(sourceElement);

                window.open(downloadLink);
            }
        }, false);
    }

    disableDownloadIframe();
}(window.top));

Enhance Yahoo! Mail 1.0.js

// ==UserScript==
// @name Enhance Yahoo! Mail
// @version 1.0
// @description In Yahoo! Mail, opens the download iframe in a new window so that the attachment can be opened if the file type is associated with the Opera browser.
// @author XP1 (https://github.com/XP1/)
// @namespace https://gist.github.com/1126767/
// @include http*://mail.yahoo.*/*
// @include http*://*.mail.yahoo.*/*
// @include http*://mail.yimg.*/*
// @include http*://*.mail.yimg.*/*
// @include http*://yahooapis.*/*
// @include http*://*.yahooapis.*/*
// ==/UserScript==

/*jslint browser: true, vars: true, white: true, maxerr: 50, indent: 4 */
(function (topWindow)
{
    "use strict";

    if (window.self === topWindow)
    {
        var disableDownloadIframe = function ()
        {
            topWindow.addEventListener("DOMNodeInserted", function (event)
            {
                var sourceElement = event.srcElement;
                if (sourceElement.tagName.toLowerCase() === "iframe" && sourceElement.hasAttribute("id") && sourceElement.getAttribute("id").indexOf("#dlFrame") !== -1)
                {
                    var downloadLink = sourceElement.getAttribute("src");
                    sourceElement.parentNode.removeChild(sourceElement);
                    
                    window.open(downloadLink);
                }
            }, false);
        };
    
        disableDownloadIframe.call(this);
    }
}(window.top));