ReplayTV, which was the first of those services to come to my attention, offers a VCR-type remote control for live TV and customized television viewing.
Using their services, you can create your own TV channel by choosing the TV programs you want to watch from an easy to use programming grid. Soon, they will also add previews that will allow you to look at the first few minutes of a TV show and decide if you want to add it to your personal channel.
Tivo offers all the same feature but also include a thumb up and thumb down button that will allow it to know what kind of programming you enjoy. As a result, it will make recommendations as to the kind of other programs you might enjoy. While the unit in themselves may be far from perfect, they seem to herald the death of BROADcasting.
When the services they offer are built directly into VCRs, recordable DVD drives or cable boxes, everyone will start creating their own personal channel and time shifting their programming diet. As a result, the long trend of getting people to watch the same program at the same time may die off, creating all kinds of new headaches and opportunities for the TV industry: headaches because they won’t be able to charge a premium for the Thursday evening spot (traditionally one of the busiest nights) and opportunities because they will be able to garner audiences for certain TV shows around the clock.
In the long run, I believe this could be a new way to watch TV. Definitely a technology to watch.