This is an image of a water drop on a glass disc, using a very shallow DOF afforded by the MP-E.

I was attempting to tempt a caterpillar to drink from the drop, and then take some in focus and some with partial focus which may have been suitable for the challenge. But it didn't play ball and so I concentrated on the caterpillar and disc separately.

I've posted a shot in pending: click to view

It shows the closest I got to the drinking water shot but also makes the disc and water a little clearer.