Do something unforgettable when you walk into the room. Take the most startling fact from your presentation –the one thing you really want the audience to remember–and find a way to slam it home that they’ll not soon forget.
Wear a costume. Use an airborne when someone gives the wrong answer to a question–or throw a candybar or t-shirt when they get it right. Play a loud music clip. Show a funny video. Drop a hardcover book on the floor.
Be creative, but do something different to get their attention.
Start out with a great success story your company or product/service was a part of. Someone else succeeding with your product, rather than your product itself being the success, is really something they’ll remember.
From my self-interest point of view, you could also use audience response technology to involve your audience throughout the presentation. Yo can choose whether you want to do it on their own mobile devices, or with dedicated “clickers”.
Different situations require different approach and thus a choice of tech, too.