This technique was shared on Photographers@Pune discussion thread. Reposting here.

Equipment:

-Canon 40D body.
-Sigma 70-300 APO DG (Poor man's tele+macro lens).
-In camera flash.
-Shutter release cable.
-Glass (Preferably with some tangy colors, mine was lemon green Luminarc).
-Water :-)
-Dropper (I used empty ballpen, time par dropper gayab ho gaya tha).
-Tripod.
-Light source was CFL bulb in the room + Camera flash.


The camera settings I chose..

Shutter Speed: 1/60
Aperture: f/5
Focal Length: 190mm.
ISO: 400 (low light conditions)


Shoot:

Put the camera on high speed continous shooting mode. Set up the tripod only slightly (approx 6") elevated above the surface of the glass. Fill it with water to the top edge, and get the camera ready on tripod. Switch the camera to manual focus. Compose the frame. Hold the tip of the pen at the centre of the top plane of the glass filled with water just about where you'd be dropping the water drops and focus the camera on it, locking the focus in place. You will need a helping hand to hold the pen, while you are focussing. Now, setup is ready.

Stand near the glass. Make sure that you are not in frame. Hold shutter release cable in one hand (mine is 5mtr long). Now press the shutter release and lock it and quickly start dropping the water using the dropper as close as you can to the place where you had hold the pen tip while focussing. It's takes lots of practice and MANY trials, so don't forget your patience for this. You will end up getting only 5-6 well timed shots after say around 100 clicks. You will eventually get the hang of when to press the shutter in relation to dropping the water, and I'm sure you'll come out with some great shots.

Most of all, experiment! Try different different angles and lighting setups. Good luck P@P!

Cheers.

Do post the results. And yess, a one more gala treat due after you get the shots...!!!