According to Big Green Switch 8 - 10% of a normal household's energy consumption is due solely to appliances that are on standby. While a study made by The University Of California estimates that the figure is anywhere between 6% - 26%.
By unplugging these appliances you can obviously save a noticable sum on your electricity bill every year. And without actually having to do much except plug them out once.
You can also use something like a timer or standby buster or the sort. This will help you out even further.
Another plus side is naturally that you are saving money while at the same time helping the environment.
So this is what I'm doing today.