This October pet-a-palooza is free for you and your furry friends. Prizes, free demonstrations of obedience and agility, free nail trims, and even a costume contest are all part of the fun—and adoption groups are on hand, so you might just come home with a new family member. Similar pet expos are held across the country from New England to Atlanta to Anchorage; see a schedule on the St. Louis Pet Expo website