If you are lucky enough to own a couple of Apple iPad devices as well as a handful of iPhone's then the iPADock could be one option for you.
The iPODock (note it's iPAD not iPad), allows up to two iPad's to be charged together. Alternatively you can charge two iPhones and an iPad or four iPhones at once depending on what you need to do at any given time.
As well as supporting the iPad and iPhone, the dock also supports other iDevices such as various iPods including the touch and nano.
On the back of the iPADock you'll find seven USB ports of which four only allow power to be fed to the dock. A connector for the camera connection kit is also included along with a bunch of memory card readers that support most makes and models of memory card.
Price wise it costs the equivalent of $70 in Japan and is going on sale at the end of September. Global distribution is also expected to happen.