Here is a cool way to charge up two Apple devices at once, this is the duaLink sync and charge splitter cable and it connects an iPhone or iPod or two of the same to the same computer, which can be very handy as many people have a couple of these devices running at the same time and if the battery was to fail on either or both then that would be a total disaster for the user.
These are the features and the specs for the duaLink sync and charge splitter cable;
Charge and synchronize two iPad, iPhone, or iPod devices at the same time with one USB port on your Mac or Windows PC
Contains a custom USB hub to coordinate connecting, synchronizing, and charging
Works beautifully with iTunes, which can access both devices
USB 1.0 and 2.0 compatible
Durable housing and heavy-duty wire holds up through wear and tear
Nine inches long (23 cm)
Works with all iPhone and iPod models except the iPod shuffle
CableJive Lifetime Warranty.
Priced at around £15
Source [Incredible Things]