At Sydney's Valhalla cinema in the 1980's I saw an Italian film (can't remember the title) where they kept a pot of garlic boiling at the back of the cinema. It worked really well!

There's also a touring French theatre troupe that does outdoor shows where they use a big fan to direct the appropriate fragrances into the audience.

Theres a contravosy brewing within hollywood on this.. what happens if a person is allegic to any of these scents ?? who will pay the insurance ???