In recognition of its increasingly connected mobile guests, Marriott Hotels is rolling out mobile check-in at 325 hotels in the United States and Canada. Marriott Rewards members can check-in after 4 p.m. the day before their arrival and will receive an automatic notification when their room is ready. Because credit card information is stored within their Marriott Rewards profiles, members simply walk up to the expedited mobile check-in desk where their pre-programmed key card will be waiting for them.