Gmail Labs added a new feature that converts an email into a Google Docs document with one simple click on "Create a document". To turn on this feature, go to the Gmail Labs tab under Settings, select "Enable" next to "Create a document" and hit "Save Changes" at the bottom.

No more copying and pasting the text from your email -- just open the message you wish to convert, click the "Create a document" link on the right side of the page, and voila, you have a brand new document which you can then modify and share! Even if you're not interested in converting any of your current messages into documents, you can easily open up a blank doc by hitting g and then w (just make sure you have keyboard shortcuts on), explains Gmail Blog.