Invited to a potluck celebration this Fourth of July and not much of a cook? Instead of bringing something unappetizing or a bottle of wine, bring something green. Offer to bring reusable plates, cups and utensils and cloth napkins. They're stylish upgrades from disposables, and they'll be a welcome addition. When the event is over, place everything into a portable cooler and wash them at home. It's the same amount of work as making food, and it's a surprising (and welcome) offer to the host.