Just out of the Gmail Labs is a Google Maps preview function, which appends a miniature map — with full scaling, zoom and other Maps features — to the bottom of any message containing a Maps link.
As always, you can enable the feature by heading to your Settings in Gmail and heading to the Labs section, where you'll find "Google Maps previews in mail" available to enable. The feature only works with US addresses at the moment, but international support is being developed. By the same token, Buzz social network users get the same kind of instant preview of Maps links when posting their updates or viewing others'.
Google Maps previews in Gmail and Google Buzz [Official Gmail Blog]