I agree, I was trying to not overestimate on my first guess!.
Look at two categories of devices, one is audio-visual: TV, DVD, video/PVR recorders, digital tv receiveres, satellite receivers, etc…
The other is “domestic” Microwaves, washing machines, dish washers, hand held
vacuum cleaner, torch chargers, digital phones, cell phone chargers, …

In each category we could assign use mode of operation over time:

1- Need it on standby,
2. Not needed on standby, really, not needed!
3. Product active (actually in use so standby effectively is off)

I think category 1 is likely to constantly be on 24×7. Category 2 is probably
lower (as people may not always keep these devices plugged in all the time)

24×7 mode would be reduced in category 3. Lets say 8 hours a day product is
required. I reckon the average #devices per household will be more like 4.
So even reducing this to (say) 16 hours a day, the average consumption would
still be about 6 watts constant draw per household.

So we must be in the 120Mw - 200MW range, surely?
An average sized new power station unit is around 800MW?? Hmmm.

Given that we humans are lazy or absent minded by nature (or both!) I cannot
ever see the answer being to “switch off” unless instigated by
rolling blackouts.

I think 5 megawatts is probably quite an underestimate. The 1 watt initiative implies to me that the average power consumption of an appliance on standby is more than 1 watt, for the sake of argument lets say it is 2 watts (alouth I expect they mean watts/hour). Lets take a conservative estimate of 2 standby items per household in the uk. There are roughly 22 million households in england and wales alone ( http://www.environment-agency.gov.uk/yourenv/eff/1190084/people_lifestyles/household/?version=1&lang=_e ) so even excluding Scotland thats 2 x 2 x 22 = 88 megawatts per hour.

I think the ‘better way’ you describe is called ‘turning things off’ or ‘not having standby mode’. Encouraging these ways is the real trick eventually energy costs might cause enough encouragement to make those better way’s happen.

Now… my pet peeve…
what about power standby mode?
Video players, DVD players, TVs, torch chargers, dustbusters, microwaves…. this is just off the top of my head.

I think we would all be surprised by the quantity of power wasters we have in the house. tot up these by looking for all the
three pin plugs in the house?

I reckon the UK is constantly burning
probably more than 5 MegaWatts of electricity just for standby mode,
oh, and its 24×7.

There has to be a better way.

Lloyd, dismissing all good things. slowly.