[KenWittlief]

pots are only designed to create a small signal, not to control any significant power - so no, you cant control a servo motor by connecting a pot to its power leads

the servos they give us, the hiTech units, are contolled by a digital pulse width modulated input, so putting a pot in series with its leads, or across them, would not create the type of signal the servo unit needs to see.

If you explain what it is you are trying to accompish, Im sure it can be done somehow - but not as simply as you want it to be.