In cases where you have more TVs than potential TV viewers (which may apply to some of the examples in this thread, or not), it can sometimes be cheaper and/or more convenient to install one receiver per viewer, rather than the usual approach of one receiver per TV. This requires that you also install some sort of distribution system to enable any receiver to be viewed and controlled from any TV location. This approach is especially attractive in the case of PVRs, because it allows you to watch a recorded show on any TV, not just on the one or two TVs attached to the PVR containing the recording.
That's what I have done at my house, where we have four viewing locations (3 rooms with HDTVs and a theatre room with a front projector) but only two potential viewers (my wife and me). We have two 9200 PVRs ("his" and "hers") to each record our own favourite shows. We use an HDTV matrix switch (Key Digital KD-MSW8x4) to route component video and digital audio from either 9200 or a single DVD player to any of the four viewing locations. We have a universal remote (MX-500) at each location, programmed to control the matrix switch, both 9200s, and the DVD player, and an IR distribution system (Xantech) to deliver the remotes' signals back to the location of the source devices.
This approach does require a lot more types of equipment, wiring, and knowledge than the usual approach, which certainly limits its applicability. However, it can compare favourably to the cost and limitations of buying or renting and installing a whole bunch of receivers.