One of the amazing things that you can do with a DSLR is configuring the shutter speed to make it capture images as fast as possible, and one beautiful subject to demonstrate is flowing water.
The DSLR can be set to up to shutter speed 1/4000, with flash up to 1/200 (for a Canon 550D).
Here is my test shot for demonstrating this effect.
|shooting settings: f/5.6, 1/200sec, ISO-400
I know this is not a very likely and glamorous subject. This is the first candidate that I laid my eyes upon so I just well took the shot.