Use proxy icons to create Mail attachments
If you’re working on a document and you want to send it to someone as an e-mail attachment, you probably know that you can drag the actual file icon to the Mail icon in the Dock to create a new message containing that file. But to do this, you have to navigate to the Finder and find the file.
There is another way: Save your work, click the proxy icon in the title bar (that’s the small icon next to the file’s name) and drag it onto the Mail icon in the Dock. This creates a new message with the working document attached to the message. (This method also works with Microsoft Entourage.)
Make sure you save the current document; otherwise the icon in the window title bar is dimmed and cannot be moved.
You can do this with Web pages in Safari or Firefox (and perhaps in other browsers) by dragging the icon to the left of the URL in the address bar; in this case, the current URL is pasted in the body of the newly created message. If, however, you are viewing a local file, the file itself that will be added to the message.
Note that different programs deal with attachments in different ways. With Mail, any changes you make to your file after adding it to a new message will not be reflected in that attachment; the file is added to the message in its state at the time you drag it. Entourage, however, only records a link to the file, so you can keep working on your document and making changes. When you save or send the message, the latest version of the document will be attached. Other e-mail programs may have different behavior, so if you use a different program, try it out to see how it works.