Lakewood Regional Medical Center last week joined a small but growing number of Southern California hospitals that allow patients to make emergency room appointments online. In exchange for a fee, instead of sitting in a waiting room wondering how long they'll have to wait, users can show up at the assigned time with the assurance they will be seen within 15 minutes or get their money back. In a region where it's routine for emergency room patients at public hospitals to wait half a day or longer to be treated ? depending on the complaint ? some say the move makes "good business sense."