I managed to get one from Adafruit last week. They restock ~weekly, typically Wednesdays, and sell out within a few minutes of the notification going out.
The microscope story a sibling comment mentioned is part of a 1970 letter from a then-NASA Director to a nun serving in Africa who asked the same question. I believe the full text is worth a read:
http://www.lettersofnote.com/2012/08/why-explore-space.html
I think these were probably water balloons. The idea is that all of those straws are connected to a single garden hose fill adaptor, so the whole bunch of balloons can be filled at once. (example: https://www.aliexpress.com/item/33011481532.html)
I abhor the single-use plastic, but at the same time water balloons are just fun in the summer. If paintballs can be made biodegradable (they're gelatin), maybe there's hope for water balloons, too.
You may be interested in a recent episode of the 99 Percent Invisible podcast (https://99percentinvisible.org/episode/atomic-tattoos/). The title of the podcast comes from a Cold War program carried out in 1952 in which students could opt to receive a small tattoo of their blood type, with the goal of creating a "walking blood bank" in the event of a disaster requiring mass transfusions.
Related to your question, the episode also explores the history of "duck and cover." It turns out it's there is some credibility to the technique. In September 1945, the US sent a team called the Atomic Bomb Casualty Commission to Japan to research and interview survivors of nuclear blasts. They located survivors just a few blocks from the explosion epicenter, who had been sheltered by concrete basements. They also heard stories of people who were killed just by shattering windows and falling debris. With just some ability to shelter, survivability might be higher than you suspect.
I believe my submission on this is hidden because of my recent registration here. I've lurked for a long time.
The press release[1] from Staples confirms ordering online is live now, and printers will be on shelves in select stores next month.
I would have thought FedEx/Kinko's would be the first to make a move on 3D technology, first as in in-store service, then stocking product.
There was also previous discussion[2] on 3D systems and their aggression toward other upstarts. Smart of them to be first into a major national retailer if they cannot compete in the 'enthusiast' space.