Originally Posted by NSILMike
To be a standards compliant USB charger, the output of the charger should be 5V at up to 500mA.
Now, having said that, the MS USB chargers for Zunes output 5V at up to 1A. So, you are safe up to that limit...but use that charger only for USB devices that you know can handle a full amp...
I suppose that was my main point really; I can't seem to find anything officially stating the current limit when charging, and am obviously then concerned about damaging the battery/device...
Edit: Alright, I've ordered a 1000mA charger - I'll post back and confirm if it works fine!