Here are some videos of me serving over 100 mph.
Some information before we begin:
Racquet : PS 85
String: Ashaway Kevlar Crossfire II , 16 gauge
Tension: 70 lbs.
Tennis Balls: regular Wilson/Penn balls 1-3 weeks old pulled out of my bag.
Shoe: Oscillates, LOL
Video Camera: Kodak 30 fps
Radar Gun: speed track II.
The back fence is a little over 21 feet from the baseline.
Here are two serves I took as soon as I got the radar gun. It was dark out but I just could not wait to play with my new toy. One is 103 MPH, and the second is 107 MPH.
http://www.youtube.com/watch?v=C2SC9Pmp-V8
http://www.youtube.com/watch?v=dvKjCsXQggc
Lastly, not sure if you could tell but I was unable to jump and explode into the ball as the arch on my left foot is bruised. As a result, I don't leave the ground and land inside the court as it was too painful.
Enjoy!