I´m trying to come up with a big list of items that could be considered "barter", things small enough to be carried around, very useful in  specific situations and easily trade-able.

Also, I´m trying to go towards the realism side here, and many things I see listed in other places don´t seem able to resist 50 years and still work (examples: small rechargeable batteries and latex condoms). Does anyone have concrete links/ideas on how long some of these things last.

This is what I could come with so far (mostly scavenged from the internet):

•   Portable water filter
•   Hand tools including hatchets, saws, machetes and general fix-it tools
•   Fire making supplies, including lighters, matches, flint fire steel
•   Sanitary supplies including toilet paper, feminine products and diapers (**)
•   Disposable razors and razor blades
•   Prescription drugs, painkillers, and antibiotics (**)
•   First aid remedies such as cough syrup, cortisone cream, boil-ese, calamine lotion and topical pain relievers (**)
•   Spirits such as bourbon, rum, gin, and vodka
•   Coffee and tea (instant coffee is okay)
•   Solar battery charger and rechargeable batteries (**)
•   Standard Batteries (**)
•   Reading glasses
•   Paracord
•   Bags, including large garbage bags as well as smaller zip-close bags
•   Plastic sheeting
•   Duct tape (**)
•   Tie Wraps
•   Heavy plastic sheets and tarps
•   Vinegar and baking soda to use in DIY cleaning supplies (**)
•   Condoms [old world latex ones (**) or currently manufactured sheep intestine ones]
•   Latex or Nitrile gloves in a variety of sizes (**)
•   Fishing gear (line, hooks, lures)
•   Knives of various types including fixed blades, kitchen knives, and box cutters.
•   Condiments and Spices
•   Paperback books on a variety of subjects (mostly technical)
•   Tobacco and cigarette rolling supplies
•   Amusements such as playing cards, crossword puzzle books, Sudoku
•   Pencils & paper
•   Pepper spray (**)
•   Garden seeds
•   Flashlights (powered by?)
•   Empty spray bottles and squirt bottles
•   Hand pumps for both air and liquids
•   Mylar blankets and tents
•   Sewing and mending supplies
•   Knitting or crochet needles and yarn
•   Electronics (computer chips, wiring, diodes)
•   Mechanical pieces (rust free valves, gear, wire, ball bearings, pipe or bags of screws)
•   Non-drug medical supplies (syringes, bandages, tubes)
•   Bullets (specific / rare ones)
•   Golden age memorabilia (pictures, maps and other media)
•   Vinyl Records?
•   Can Openers!
•   Candles
•   Compass
•   Precious metals and gems (gold and silver)

(**) these are the items I have doubt about being still operational/usable after 50 years, I´d love some feedback.