Have pens and notepads at the event so people can have something to jot down questions, ideas, etc. If you are performing a carrier specific event, contact your local rep to see if they have any branded pens / pads you can have. Otherwise you can always order your own custom materials or simply use generic pens and pads from your local office supply store.
These are also great to place at the seats where you would like people to sit down. Possibly add a business card there as well so they have your name in front of them.
TIP: If you are using generic note pads, you can always place a label on the top of the notepad with your contact info. Just print your info on a return mail label and placed it on the top of the pad.