Watch network TV online with Prime Time Rewind
What Prime Time Rewind does is present every network show that's available on the face of a cube. You can shift the cube side to side to see what's on each network. Or you can shift it up and down to find comedy or drama programs sorted by category.
When you click on a program, it will start playing directly from the network web site. In fact, the network web site will open up on your screen while the Prime Time Rewind navigation options will hang out in a sidebar. That's a really smart move, because it means you're basically visiting the network web site and viewing the videos exactly as the networks want you to. Thus, there's no good reason to sue Prime Time Rewind.
If the cube thing isn't doing it for you, you can also just type the name of a show into the search box to see if it's available. The biggest problem with the service is that there's no easy way to search for a particular episode from the Prime Time Rewind website. So if you're watching a show that's available on another site like Hulu, you might have an easier time finding what you're looking for there.