Thanks for the replies!
I haven't had any accidents with copper foil tape (yet!), but I can see how one might get hurt from it. I wouldn't keep it away from the kids just cause it might cut them though, as many other tools are just as dangerous and they have access to those with no problem.
AndyC_772, the contact resistance is like 1k in the video, and since then I've gotten it down to less than 10ohms. Breadboards are great, but I wanted something that could stick a circuit onto nontraditional mediums, was visually a little more approachable, and was more efficient for a workshop or classroom environment. Even when using a mini 170 point breadboard, for simple circuits students typically leave a huge amount of the breadboard unused. In the past I've actually sawed those mini breadboards in half to save on cost.
Andy Watson, I haven't tested it in a high current short circuit situation, but I definitely should at some point! I doubt that it has any more of a fire risk than a regular high gauge wire. As for the use as an electrode, when we use educational tools like the MaKey MaKey or the Drawdio we always tell the students that they are special exceptions where electricity can safely pass through their body, and that they shouldn't assume that for any other device. As for burns, I haven't seen any evidence that short term exposure to miniscule currents is terribly damaging, though I have heard from people that practice transcranial dc stimulation that irritation of the skin can occur after several minutes of mA's passing through their heads
I really appreciate the feedback so far! It seems like the novelty of a conductive tack is intriguing but people would rather stick to tried-and-true prototyping techniques. Any other thoughts?