Hempstead has authored, coauthored, and updated over 60 guidebooks that have sold over 800,000 copies. His books are available worldwide and have been translated into multiple languages. Major guidebook clients include Avalon Travel, Frommer's, Michelin, Odyssey, Dorling Kindersley, and Michelin. His travelwriting has also appeared in dozens of different magazines and online for clients such as Alaska Airlines, Expedia, and Microsoft Automaps. He also writes and edits for corporate clients such as Parks Canada and Travel Alberta. He is an academy member of S. Pellegrino World's 50 Best Restaurants; has spoken on guidebook writing to a national audience; has contributed to a university-level travel writing textbook; joined Tony Wheeler and Tim Cahill as an interviewee of Rolf Potts; and is called on by CNN Travel as a Canadian travel expert.