In lieu of more traditional wedding (or other party) favors, host a candy bar! Guests can receive little paper bags or more decorative pouches with their names and seating assignments on them which can double as candy sacks for later in the evening.
How To Set Up A Candy Buffet (Step By Step Instructions!) from Tonya Coleman of Haugen Haugen Haugen Mitchell Event Design. This is a great post, and it should help me figure out how much candy to buy!