The upcoming "Hopper" DVR from Dish Network solves this problem in an ingenious way. They have a feature called "Primetime Anytime" that records the entirety o

The upcoming "Hopper" DVR from Dish Network solves this problem in an ingenious way. They have a feature called "Primetime Anytime" that records the entirety of primetime (8-11pm) programming on the 4 major broadcast networks (NBC, Fox, ABC, CBS) for the last 8 days. That means you can turn on your DVR and watch anything that aired in primetime in the last week. The way they achieve this is by silently recording the networks in the background. The DVR has a 2TB hard drive, of which about 500GB is allocated to this feature, I believe. (Note that doing it this way also absolves Dish of having to negotiate with the networks a la Hulu.)