I have a AC to DC converter that was originally used for recharging the PSP, I stripped the 2 wires of the output and was wanting to use it for my arduino instead of using a 9V battery, it's output is 5V 2000MA, is there a way to reduce the current in order to use it for the arduino and im guessing the 5V is enough to power it...right? Im kinda new to electronics and the arduino so any help is much appreciated :D. Thanks, Liam.
You don't need to reduce the current.
2000MA (2 amps) means the power supply is CAPABLE of supplying this (without overheating). Anything less than this, and your device will work perfectly.
Your Arduino will DRAW a certain number of milliamps (amps), this is the amount of current that will ACTUALLY run through your circuit.