WHITINGHAM – The Whitingham Vermont Holiday Pop-up Shop has a long name, an irregular operating schedule and will celebrate 10 years of business in November. The shop has 11 vendors, all local people, and the merchandise is generally limited to antiques and collectibles, and various handmade craft items. “It’s doing pretty well,” said Darlene Betit, the organizer of the joint retail effort, the landlord and one of the vendors.