For the LED blink test, it is advised to use a 220Ohm Resister.
I got the logic behind that, which is to keep the current drawn from the board to .02A. (I(0.2)= 5V/220).
So thats fine.
But for the potentiometer test stated here : http://arduino.cc/en/Tutorial/AnalogReadSerial, I see there is no other resistors than Potentiometer. And it tells about bringing the potentiometer from 0,1 and so. So, if thats 1 Ohm resistance, I = V/1 => 5A.
Am I missing something here? Please correct me :)