Hi!! 
I´m about to test servos with arduino (i´m newbie here) and time ago i´ve read servos produce problems in the voltage-cables and because of that are to be used with an extern independent V-source (4x1,5V Batterie for example)
Is this true, or can i power the servos with the Arduino connected per Usb?
If not, i would like to try with a 9v-Batterie....would be enough using a resistor as voltage-divider in line with the motor between motor and +9V?
Thanks in advance
With a stall current of 440ma, you MIGHT be able to get away with powering one from the arduino. Any more than that and you're just asking for trouble. A 9v battery isn't a great power source either, as you'll be able to drain it pretty fast. I'd use a pair of lithium rechargeable batteries and a 5v regulator.
Thanks Josh.
Until now it all works great, the only question I´m making myself:
Why manufacturers dont show the pulsetime for 0°, 180°??? 
I mean is the only way to fit it just experimenting with the values in the sketch or there is somo more "elegant" option??
Good question. The only common theme seems to be 1.5 mS for midpoint and pulses anything from 1 to 2 mS but no standard for anglge vs pulse width.
Russell.