Wow, thanks for the fast reply!
What would be a good shutter speed to use to induce motion trails? I think that would make a pretty sick shot if my friend had some motion trails while in mid air.
Also, while using a tripod, what would happen if I set the camera onto the tripod, used a shutter of say... 1 second at the most? Take the picture while my friend is doing a trick.
Would it just be a big blur of movement?
For the shutter speed, if you want to pan with the subject, you need to take a couple of things into consideration:
A) How fast is he or she going?
B) What's your distance to your subject?
C) How large is your frame?
Basically, if your subject is going fast, you won't need a fairly slow shutter speed, as long as you can pan with him that instant he or she flies by.
If your subject is going at a moderately "average" speed, then you may want to slow your shutter down. I suggest going into Shutter priority and starting from 1/30th down. Remember that during your panning motion, try and keep the camera as level as possible.
I suggest that you retain from making a tight crop of your subject in the frame. If you can get your subject at a reasonable area in the frame, keeping some bleed/crop room around the side, that will be much better.
If you want your subject to have a motion blur, you're probably going to want to fire your flash using a Rear-Curtain/Rear-Sync flash. This will give you that "motion" trail if your subject is either going faster than your shutter, or if you have a moderately slower shutter while panning.
If you put your camera on a tripod and fire a 1 second or more exposure, and your subject flies by the frame, everything that has been still will be in sharp focus, while a completely blurry "ghost" is in the frame. Not exactly a nice image