For just 10p more than a standard small pin AC-3X charger you can get this energy saving charger which reduces the standby consumption by 90%! I just noticed this after my previous post, so sorry for the similar post - but I think this one is more interesting.
Genuine Nokia High Efficiency Charger AC-8X uses 94% less power than conventional charger designs. Charge your battery with a clear conscience. The AC-8X charger minimises the no load energy consumption in case you forget to unplug it from the power socket. This environmentally friendly multi-voltage charger helps you to make a big energy saving difference. If you forget to unplug, this green performer uses just 10% of the standby power used by conventional chargers. Try not to forget though! Charge any Nokia device with a Nokia 2 mm charging interface. Supplied unboxed.
Lots of other chargers on discount too -
There's even 1% Quidco for the keeners ;-)