Copying and pasting from Safari when using the Reader function has two modes, depending on where you are pasting.
If you select, copy, and paste the text into a text editor, you get something that looks like this:
Britain Plans to Decentralize Health CareHowever, if you paste your copied text into a new mail message in Mail.app, the source URL is prepended to the text, like this:
LONDON -- Perhaps the only consistent thing about Britain's socialized health care system is that it is in a perpetual state of flux, its structure constantly changing as governments search for the elusive formula that will deliver the best care for the cheapest price while costs and demand escalate.[...]
http://www.nytimes.com/2010/07/25/world/europe/25britain.html?_r=2&hp[crarko adds: I tested this, and it works if Mail is set to use Rich Text as the default message format, but not if it's Plain Text. In TextEdit it made no difference, the URL was not inserted. If you use the little 'Mail this page' icon in Safari Reader, it forces the new message to be Rich Text and adds the URL.]
Britain Plans to Decentralize Health Care
LONDON -- Perhaps the only consistent thing about Britain's socialized health care system is that it is in a perpetual state of flux, its structure constantly changing as governments search for the elusive formula that will deliver the best care for the cheapest price while costs and demand escalate.[...]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20100725135725253