Browser Address Into Mailto

Is there a way---using HTML or script---to have the browser address (URL) of a
page automatically load into a mailto (i.e., I'm trying to find an easy,
automated way to do a "Send this page to a friend" kind of thing, and would
like the URL placed in the actual email message automatically. Any
suggestions, or know of any scripts/products that automate this (so I can put
it into the template and not have to hand-code the URL on every page)?

Thanks much,

Simmons