I have been picking up and developing a fork of Grant Heaslip's Safari extension URL clenser which removes all sorts of un-necessary junk for the URL so that you can easily pass on a clean URL to someone else. Things being removed include:

• Google Analytics parameters (utm_source=, utm_medium, etc.)
• Youtube related parameters (feature=)
• Partner tracking stuff for NYTimes, Macword, CNN, CBC Canada and The Star

You can download my version here: url_cleanser.safariextz