QuoteURLText is a handy Firefox extension by Jay Palat that copies online text to the clipboard with page title, URL, and date. The extension's formatting options allow the user to arrange any or all of these elements to taste.
I find QuoteURLText's formatting options helpful in working with online material that I want to quote. I have QuoteURLText configured like so:
Three — no, six cheers for QuoteURLText. I hope that it will soon be working with Firefox 3.5.