I've seen this idea baked in part, usually on the Sci-Fi channel, which will offer a chat-room dedicated to a particular episode or series of this or that, running only while the show is on.
What I have in mind for this idea, though, is a continuous service which offers not only running commentary of the program you might be watching, but the availability of historical review of commentaries of shows that are over (more like a message board where you can go back and trace the progression of comments).
I envision access to this service both by a simple keyboard which is part of the television set, and also by web access where other users use a more robust messaging system on their computers alongside their television sets.
The service would provide for filtering so that you'd receive comments only from individuals whom you find interesting (which can be determined by popularity polls and other message board sections), and for some off the cuff content rating of television shows by users, which would have an actual 'hot-or-not' rating system for whatever show they were watching while they were watching it.
Access to the server would be free, supported by the web-site ads, and console sales for those who purchase the television attachment.
For the console, either there would be a two line black bar superimposed on the screen, top line for msg scroll, and bottom line for msg entry, or the console could have a small LCD screen to serve the same purpose.
The difference between this and the rest of the internet is that it would be dedicated, monitored for non-tv-related content (which would be removed), and also made as simple to access as possible to appeal to television watchers instead of people who draw more of their entertainment from television-independent web surfing.-- Soterios, May 14 2005 Halfbakery: Virtual Living Room (1999) Virtual_20Living_20RoomClose. [jutta, Mar 04 2007] Maybe a different name ... proper naming of ideas seems to have more bearing on acceptance than it rightly ought to. But, hey, what are you going to do?-- Soterios, May 15 2005 who are you talking to?-- po, May 15 2005 I seem to have gotten your attention.-- Soterios, May 15 2005 I smell milk.-- skinflaps, May 15 2005 Chocalate milk?-- goober, May 15 2005 Audience participation TV marquee. Sorry, I see this as distracting and confusing. Beside my objection, rutabaga rutabaga.-- reensure, May 16 2005 I can't find an online version of the comic, but did the title come from a Calvin & Hobbes strip?-- Zimmy, May 16 2005 I think this would be like that wannabe guitarist that comes with you to a gig and spends the whole show commenting on the various techniques in use and forgets to listen to the music. Which presumably means that there's people out there who will use it.-- wagster, May 16 2005 [Wags], good point. It would definitly be a niche market.-- daseva, May 16 2005 random, halfbakery