Adding a bit of haptic feedback could take this idea in so many directions ... here’s an article on building your own metal detector.

"What can it be, I wonder?" Pam talks about metal detecting and how her finds provide an intriguing insight into the past. My hobby is metal detecting. I go out in all winds and weathers to farmland, ...

But while metal detecting is a well-established hobby with thousands of dedicated adherents, it can be difficult to get started. Though easy to use, some metal detectors are made to be easy enough ...

Metal detecting is a fun pastime, even when all you can find is a little bit of peace and a whole lot of pop tabs. [Huygens Optics] has a VLF-based metal detector that offers much more feedback ...