This is from a guy answering a question about freezing the action at night iwht a flash. Read it 3-4 times... its awesome.
If you want to freeze motion (that is, no blur at all) what you want is LESS ambient light and more flash!
Consider: How long you have the shutter open is irrelevant if there
is no light (or essentially no light) entering it for part of the
exposure.
A flash at 1/1 power has a duration of about 1/1000th of a second,
at lower powers, the duration is even less. This means that at, say,
1/16th power, your flash duration is often less than 1/10000th of a
second, much faster than your shutter in broad daylight. You can
therefore pretty much ignore the shutter speed in terms of determining
flash exposure as a 1/1000th of a second flash burst will add the same
amount of light to a 1/15th of a second shot or a 1/250th of a second
shot. The shutter speed will only impact how much the ambient light
adds to the exposure - higher sync speeds are useful in the daytime
when you want to darken the unflashed parts of the exposure. Aperture
does matter for flash; a wider aperture increases the flash's power in
the same way that it would for ambient (constant) light photography.
Therefore, if you really want to freeze action (like those
photographers who take pictures of balloons bursting or glass breaking)
the logical solution is to light the entire scene with flash, ideally
by using multiple flashes positioned to give some dynamic lighting, and
using the flashes at less than full power to bring the flash duration
down. Anything exposed by ambient light is going to show up as a blur,
but by increasing the flash power and closing down the aperture you can
bring the ambient exposure down to near-black and have everything
exposed in the 1/1000th or less of the flash burst. Shooting in full
manual mode and chimping off the rear screen is probably the best way
to do this.
Summary:
Get the flash off the camera
Have the flash provide the light for the exposure
Use the shutter speed to control ambient light
Use the aperture to fine tune flash power
If you want, Get multiple flashes and some stands and wireless triggers (none of these have to be expensive)