It wasn’t long ago I was looking for one of these. Unfortunately I wasn’t able to find a retailer that looked ‘trustworthy’ enough or a cable that could charge both connected devices - fortunately, thanks to RedFerret, now I have.
The duaLink cable will be very handy to you light travelers out there or those of you with limited USB connections in your computers. It costs a mere $25, ships internationally and works fine with iTunes which can access both devices simultaneously.
Get one here.