A friend recently told me that he could find out through Google what
websites I had visited.  Is this so?  If so, how?  I understand the
history provides information on past few weeks - but I want the last
15 years.

Hi markfromboston-ga,

  It is not possible for your friend to download
  your history of website browsing from Google.

  I believe that your discussion is related to
  the Google Toolbar:

http://toolbar.google.com/

  The Toolbar can optionally report back to Google
  about the websites that you visit.  Hence, it
  is conceivable that Google saves that information
  and could produce a list of what sites you visited
  during the past few weeks.

  Still, Google's privacy statement, found here:

http://toolbar.google.com/privacy.html

  indicates that they would protect any such list.

  As for obtaining a list for the past 15 years --
  wouldn't that be nice!  I would want that, plus
  every email (or voicemail) that I had ever sent 
  or received.  Unfortunately for us, neither the 
  Google Toolbar, Google, or the World Wide Web, 
  for that matter, have been around for that long.

  I hope that answers your question.

                 dogbite-ga