If you run across a cool website and want to email that site to a friend, probably the fastest way is to press Command-Shift-I. This opens Mail, and inserts the Web URL into the body of your email. Now all you have to do is type the recipient’s name, enter “Check this site out” in the Subject line, and click Send.
Then all you have to worry about is their spam blocker stopping your email from getting through with such a generic subject in the title. (Note: If you want a super-slow way, highlight the website’s name, go under the Safari menu, under Services, under Mail, and choose Send Selection — it basically does the same thing.)