With the advent of digital delivery systems in CATV, fast data channels of multiple megabytes per second are feasible. Such channels open new possibilities for multimedia interactive applications. They can be used to provide an enhanced TV guide service that includes still pictures or even video clips. They can provide an electronic advertising magazine with pictures. Under appropriate conditions, they can lead to a variety of CD-I like applications. This paper outlines some of the new cable services made possible with fast, one way data channels, and explains the issues to be addressed in developing those services.