Not talking about display, but experience and giveaways. How do you be the coolest booth in the building?
Or run a theme to your stand. We got an accounting firm to dress up as "Jack and the Beanstalk" characters and they walked round the whole show interacting with visitors and being photographed.
Everyone came to the client website to see their photos with the Giant afterwards..... where on the same page an offer was made.... Cute, engaging and very simple to put into practice.
http://lovetogrow.co.nz/annual-accounts/ is the offer page!