Airpnp is a new app that may be the most useful thing to bring to a Mardi Gras parade in New Orleans. It's similar to Airbnb, but for bathrooms. It allows people to rent out their porcelain facilities to folks who just gotta go! The app has locations, photos, and reviews for bathrooms in private homes, churches and businesses. Places like 'Louisiana's Pee Palace,' 'Hotty Toddy Potty,' 'Napoleon Sweet Relief,' and 'Chestnut Hut.' A few are free, some charge a minimal amount, and others are for charity. Download from the App Store.