Last year I planned an association meeting with a back-to-school theme. You can use elements of this if you're doing a philanthropic event that benefits education, or if the setting for your meeting happens to be at a school, or if it takes place in early September.
This particular meeting happened mid-day, and members were expecting some sort of light snack. Sticking with the theme, I created the following:
Personalized snack bags for each attendant
Each bag had a selection from the above.
These bags got a great reaction, and trading did in fact happen! It was completely cheap and easy to create - just some lunch bags, sharpie pens, and some snacks from CostCo. I think it ended up being about $3-$4 per bag. The signs were made with an apple border that came bundled with MS Office, and Kristen ITC font.
Other elements to consider:
Create a Welcome sign on a portable chalkboard
Offer crayons, colored pencils, and butcher-block paper for brainstorming sessions
Seat everyone on those really tiny plastic molded chairs (KIDDING! Guests should always be comfortable, and I know my rear has outgrown those chairs!)