Anyone who has a smartphone knows how bad battery life can be after some heavy online usage. With a portable charger, users don't have to worry as much about battery life and can top up their phone while on the road. These work simply by plugging in to the USB socket of the phone. Of course, you have to remember to charge the portable chargers overnight before you leave, otherwise they won't be of any use. The Belkin (left) can be found in most consumer electronics stores, the Veho (right) is available from JB Hi-Fi.