Sure ya can, it's done all the time in message board type
signs..  With up to 5K+ bulbs you need zero crossing to keep
life reasonable, and you also need dimming for night.  Just
don't fire the triac on the negative (or positive) side of
the cycle and you get ~50%.  Not high resoultion like
starting partway through the phase, and you can't go past
1/8th or 1/16th easily with reagular lamp bulbs or you'll
get flicker, but still pretty useable dimming for most
applications.  Set up a sign with several hundred bulbs
without ZC and see how many failures you get in a week.  And
check out the cool electric bill you'll receive for your
efforts!
Alan


> You can't do dimming with zero-crossing firing :-(
>
> BillW