This device seems extremely interesting in terms of potential (WEIRD) uses: ECH2O Dielectric Aquameter:

The ECH2O Dielectric Aquameter is a new, low-cost sensor for measuring volumetric water content of soil and other porous materials. It uses new technology and durable materials to enable you to monitor moisture content over a wide geographic area. Best of all, it is inexpensive enough to allow you to install several of them in your field or plot without breaking the bank.

Why do I blog this? okay I need a coffee...