The Intelliplug is easy to use, saves energy (and money and carbon emissions) and is a great, simple product for the house. It reduces standby power usage in a very convenient way. You choose a "master appliance" (PC), plug this into the Intelliplug's master socket, then plug other appliances that are used with the PC into the peripheral sockets (monitor, speakers, printer etc). When the PC is switched on, power is given to all the peripherals at the same time. When the PC is switched off, power is cut (after a short delay) to everything, and nothing is left on standby. You also get surge protection for all appliances plugged into the Intelliplug.
The intelliplug itself consumes around 0.5 W, which is much less than the standby power typically used by PCs, monitors, printers etc. Standby usage for a group of PC appliances should be cut by at least 90%.
I bought both the desktop and TV/audio versions of the Intelliplug. Before I got them I wasn't sure about the differences between the versions, and there are two main differences. The basic functionality is the same: when the master appliance is switched on, power is supplied to the two peripheral sockets, and when the master appliance is switched off, all power is cut from all the sockets (nothing left on standby). The main difference is that the TV/audio version has a small attachment that responds to a remote control, so the switching on/off of the power to the sockets can be done with your TV remote. The other difference is that the TV/audio version has one of the two peripheral sockets dedicated to a Sky digibox (this socket is treated differently in the way it is powered down). So the TV/audio version has just one "normal" peripheral socket controlled by the master socket, though you can easily plug in a four-way adaptor to get more appliances controlled by the master socket. With the desktop version, both peripheral sockets are controlled in the same way by the master socket.
I've been using it on the PC for about 2 weeks and have had no problems at all. Switches on and stays on when you need it, powers off only when you hit the off button on the PC.
NB there's a third version designed for laptops, which have different power usage patterns to desktop machines.
Overall: a simple and effective way to cut down on electricity usage and save money.