look at this
http://www.youtube.com/watch?v=qj4Er2jzt0Q&mode=related&search=
http://www.youtube.com/watch?v=7-HVKTNxI0s&mode=related&search=
http://www.youtube.com/watch?v=nn0cGN6F4UQ&mode=related&search=
one of the site http://www.rc-sub.com/Projects.html
must be see
http://www.youtube.com/watch?v=a9dYuYr9Vos&mode=related&search=