I've engineered a fair number of inexpensive DIY camera hacks. This one is by far the cheapest: it's free! Simply place a drop of water on the phone's lens, carefully turn the device over, and the suspended droplet serves as a liquid lens. Behold:

Droplet images are dreamy, blurred at the periphery, and just a little bit...wet. But the tiny subjects underneath are magnified with sufficient resolution for an impromptu microscope. Indeed, I started playing around with the technique after reading that the U.C. Davis iPhone microscope team experimented with water before moving to a solid lens.

After spending a few hours this weekend with a slightly moist iPhone, I am pleased to report the following:

It works!

Larger, rounder droplets lead to higher magnification, and as the droplet evaporates and shrinks magnification decreases.

The liquid lens is jiggly and sensitive to vibrations. The phone should be placed on a stable platform for maximum clarity. For these photos, I coopted a pair of short drinking glasses as a stand.

Image quality is not as sharp as that provided by solid, commercially available clip-on lenses like Olloclip. But hey. You get what you pay for!

Water is not generally good for cell phone electronics, so be careful when applying the droplet.

Below are my attempts at iPhone water-graphs.

If you try the technique, I'd love to see your results! Drop a link in the comments, or send me an email.