Viacom is getting its toes wet in the waters of Hulu, the joint venture set up by NBC and Fox to showcase TV programming on the Internet. After balking at putting any of its cable content on Hulu's platform, Viacom announced Monday -- to the surprise of many industry observers -- that it would begin providing full episodes of The Daily Show with Jon Stewart and The Colbert Report on Hulu beginning Tuesday. Both shows air on the Comedy Central cable network. In its announcement, Viacom indicated that it regards the modest entry as a test and that it will add more programs if it proves successful.