It happens all the time. You're working on a document or you just finished editing a photo and now you want to send it to someone who's been waiting for it. You need to send it fast. The old fashioned way would be to save it, close it, bring up your email app, create a new message, find the document and then either drag it into the email attachment area or click the attach button in the email program and go digging for the document to attach.

Here's an easier much slicker way to do it.
1) Save the document you just finished, but leave it open.
2) bring up the new message and address it to the person you want to send the document to.
3) move the windows so that the document you want to send is on top, but you can still see the new email message to send in the background
4) at the top of the document window to the left of the title of the document there is a little icon representing the kind of document it is or a thumbnail of the image. Drag directly on this icon and drag it into the attachment area or body of the email message (depending on the email app you use) and it will attach it.
5) Send the email