I've got the Hella 500 driving lights on my bus; they're wired on a separate
switch and I use them to supplement the low beams.  They are SWEET (in fact,
I'm thinking of putting a pair on my Saab); the key is to take your time
aiming them.  I've never had anyone flash me, flip me the bird, etc. etc.
with these even though they are quite powerful.  The setup is perfectly legal
here in Mass.
Pics available at:
http://www.offthehill.org/~dan/mudskipper_photo_gallery.html

> Driving lights will not improve the performance of low beam headlights as
> they should be wired to only come on with the high beams.