Now, guests at select Le Meridien, Westin, Sheraton and Four Points properties around the world will be able to use their smartphones as keys. The top five SPG Keyless cities are New York, Chicago, Atlanta, Dallas and Miami, while the top five countries based on usage are the United States, China, Canada, Hong Kong and the United Kingdom. Additional properties will be going live with SPG Keyless in the coming months. Get the full story at Successful Meetings