flip.tv was the primary product and web site of my last company, the startup Appeligo, Inc. Appeligo operated for over a year doing research and development on flip.tv and its technology, and spending a lot of time doing fund-raising (unsuccessfully, I'm afraid). But we did produce an intriguing product that monitored and extracted closed captions from several different television channels, 24 hours a day. The closed captions were combined with TV Electronic Program Guide (EPG) data and indexed via our search engine to support Google-like search for TV shows. You could search for a program by name, description, or even by the topics discussed during those programs. Here is a short YouTube video showing how it worked.
Our first concept was more of an interactive TV solution that used close captions to automatically discover show context, to generate search results and ad content. Here's the original demo.