Earlier quoted context omitted.
I've got 3 USB chargers in the house, including a Kindle charger, and none of them inter-operate at all. Ridiculous.
Out of curiousity whereabouts are you based? I'm in the UK and have about 5 different USB chargers, and they all play nice with each other.
I live in the US.
The chargers look like they'll work together. For example, the Kindle charger will make my pocket camera light up its charging light, but after a minute or so, it goes out, as if the charge has completed. In fact, though, the battery is still dead. The other combinations of cell phone / camera / Kindle chargers are similar.