Brando has just come out with a new universal battery charger. It works on the same principles, jaw-grip/adjustable electric contacts, as their previous Thanko version. This little gizmo is designed to be portable and draws its power from a USB port. It can supposedly adapt to different voltages.
On top of that, it's even keyring mountable. If lugging around all those different chargers gets to you, this is a nice little lightweight solution. It's available now at the Brando online store for $12.