I use, and can recommend, this charger:

http://www.giantcod.co.uk/power-a606-du ... 05325.html

Essentially the same as some of the chargers that have been linked to (i.e. same LCD displays and menus, same four control buttons) but this has a built-in power supply as well as the option to get power from an external source, so you don't always have to lug an external supply or big battery around with you.

Comes with a decent selection of charging connectors as well.