I got together with a few other experienced photographers last night to do some experimental type shots.
One of the series involved putting drops of a water and glycerine mixture on a piece of glass and shooting a model who was standing behind the glass, while focusing on the streaks of "water". This results in the streaks being in focus while the model is out of focus.
Overall the technique is interesting, but the recent spate of warm weather conspired against us. The studio was quite warm and the lingerie wearing model was the only one who was dressed appropriately. The downside of all the heat was that the mixture on the glass was not viscous enough and ran more than desired. Am going to think about trying this again, once the air conditioning system has been turned on again, or next winter when the studio is naturally cooler.