Travel Technology - Nano 1A or 2A charger ok?

Can I use a 5v 1000 mA or 2000 mA adapter for my Nano? I usually use a regular USB charger, which is 500 mA. For that matter, will the higher power chargers hurt a Blackberry?

thanks

Amazon UK sells 1000 mA charger for the Nano, so that would seem ok:
http://www.amazon.co.uk/BLACK-MAINS-CHARGER-1000MA-VIDEO/dp/B000WFNTEC

The Ampere rating on a charger specifies the maximum current that it will safely supply. The device being charged determines how much it will take.

Someone else said voltage is like pressure, so you don't want to exceed rated voltage, but amperage is available current, so it's ok to exceed rated amperage.