Awurl, “the Awesome Highlighter,” is just that: a great way to highlight specific parts of webpages and send the page, with highlights, to friends. You can also save the highlights for later, or use the link as an informal citation, of sorts. 

Best of all, the website has a bookmarklet (drag and drop that to bookmarks bar) and a Firefox add-on (direct link) which makes everything super easy to do. Click the bookmarklet or the Firefox button, highlight a few lines or words, and get the URL from the top bar, and send it away.