In the United States, the incidence of biliary tract cancer and gallbladder cancer has been estimated to be 6,000-8,000 patients per year. Currently, there is no standard therapy for these tumors once the disease has spread and is inoperable. Recent small studies with gemcitabine have shown a positive response rate. The investigators plan to test the combination of gemcitabine with cisplatin for biliary tract and gallbladder cancers.