Strength vs. Speed

The age old question that always gets asked is:  Should you be strong or fast?  Both would be a great combination but if you could only have one, I would take speed every single time.  Strength is important.  You need to be strong to hit it out of the rough and it does help to have strength to create speed.  But strength is overrated if you have speed. 
Speed is somewhat genetic but can be increased.  Golfers with fast hands have a tremendous advantage.  You need speed to get the ball  in the air and to carry it a decent distance.  Speed is in your hands and arms.  Speed is the swishing sound you make when you swing the club through the air.  The louder the sound, the more speed you have. 
There's a few training aids on the market that help create speed.  The Orange Whip, the Swing Fan and the Speedstick all serve a purpose for increasing speed but each is a little different.
The Orange Whip helps promote lag and gets you to swing on plane.  Lag is a byproduct of developing speed and you need to swing on plane to mazimize your speed.
The Swing Fan is a very good tool for creating resistance.  As you swing the fan, the rutters promote resistance in the air so it forces you to 'step on the gas.' 
The Speedstick is a pole that has a meter for reading clubhead speed.  The meter is decently accurate and gives you a quantifiable way to judge your swing speed.
All are good devices to increase your golf fitness.  The bottom line is that speed is a necessary component to maximize your potential in golf.