Something I have been looking at too and as a result I went to Maplins today and bought an 'Energy Meter' to work out how much I use. Wanted it just for my PC after blowing up the power supply recently, but I have been going around the flat and seeing what uses what - I got quite a shock!
Leaving the TV on standby, which everyone goes on about only uses 5 watts. But my DVD recorder and SKY Box together use 25 watts on standby! That believe it or not is £20.68 a year at my current electricity costs! Add the TV into the equation and all 3 on standby for a year comes to £24.96. I need to start switching this crap off! Whats mad, is that my HiFi which is a powerful beast only uses around 40 watts when it's pumping out as load as I dare! Not much more than just having the other stuff on standby. And the TV switched on uses 80 watts - another reason to listen to music, instead of watching rubbish.
I did see a really neat thing, which will help - a remote plug. Hook all this stuff up to it and you can turn the whole lot off by a remote controller, instead of scrabbling around finding sockets etc.
GG
EDIT: I normally leave my printer on standby too (9 watts) - well that's £7.50 a year! My broadband router too, on 24/7 another £5.82 a year, but that's not so bad as I'm online a lot! But it all adds up......?