I think it's better *not* to have lots of gimmicks. I've been to many recruitment and motor shows and there were always people divebombing the stands to grab the balloons, mouse mats, pens and whatever other crap they could get. It was hard for genuine customers to get to those stalls.

Do you have a one-page flyer or business cards with a sample of your work on it? That might help too, so there is something useful (and cheap to produce) for punters to take home

Good luck!