Okay. I found
CallerTV,
TV Messenger, and
Caller IDTV. They all use composite video passthrough, which I'm not sure I want.
(I love this quote, BTW: ``If you are using S-Video from your video source to your Television then the CTV1-S is for you. The CTV1-S combines a Caller-TV unit with S-Video Adapter Cable. This cable allows you to connect Caller-TV and keep the high quality S-Video signal.'' I love the concept that passing S-Video signals through a composite device will somehow ``keep the high quality S-Video signal.'' Hah!) Also, it requires that my TV be on, which, while a niche that exists, is not exactly the one I'm in. I'm lazy all the time, not just when I'm watching TV.
Good call, though. That's almost what I want.