http://s81.photobucket.com/user/merlinblencowe/library/U-Boat%20Sub%20Octave?sort=3&page=1Clip here:
w w w.freewebs.com/valvewizard2/Uboat.mp3
(remove the spaces in www, or freewebs breaks the link)
It sounds pretty great, and as far as I know, there aren't really any DIY effects that do this without fuzzing up the signal.
Vero would be great!