It's easier than you think...
Setup
1. Sink
2. Colored bowl
3. Camera on a tripod
4. Flash
Execution
1. Fill up the bowl to the desired level with water. Put the bowl in the sink under the faucet arm.
2. Setup the camera and aim down at an angle so that the you see the surface of the water with the color of the bowl behind it.
3. Turn on the faucet until you are getting a drip every few seconds.
4. Fire away...you will have to work on your timing, but it gets easier as you play.
One thing to keep in mind is that you don't need a macro lens to do this. I got a few nice ones using my 28-135.
Get creative. You don't have to use a bowl...you can use the sink itself (follow my link) or a shot glass (84netgal has a few nice ones in her blog).
Here's my shot using the divider between my sinks:
http://www.troyschneiderphotography....8504a8b18.aspx
Hope that helps.
T.