A lot of our readers seems to be avid campers and/or dedicated doomsday preppers, because they’ve bought a ton of LifeStraws.
If you aren’t familiar, these allow you to sip directly from basically any source of fresh water you find in nature, and the filters will catch 99.9999% of bacteria, and 99.9% of parasites. That could come in handy during camping trips, or as you cling to life in a future post-nuclear hellscape.