Given the somewhat eclectic diversity of the users here, thought I'd mention a site that has an interesting turn on moving around an SD chip, or other little things. I'm not affiliated with them, other than I get the Cold War Times newsletter and these folks are a good sponsor of their museum & historical efforts. Jus thought some might find them interesting.
Check out their hollowed coins, nuts & bolts, and other bits (the Radiopacity tab is interesting) and their FAQ.
Happy trails! (sunglasses ON)
Interesting. I have seen these before.. What I would like to see if antennas hidden in wooden furniture.. A friend of mine has a furniture manufacturing business, and I wonder if there would be a market...