Waterproof storage for small stuff

Spare AAA batteries kept safe until needed 

Boba straws are available in black, clear, and neon colors, up to a foot long and 1/2 inch in diameter.

They are useful to package any number of small items, including things like the following:

matchestoothpicks
sewing kit
salt or pepper
chili powder
SD cards (red=full cards, blue=blank)
ibuprofen, vitamins, or meds
AAA batteries
watch batteries
lockpicks
escape plans, one-time pads, maps, a hundred dollar bill
a tiny USB drive
a pinch of dirt from a magical castle
a small transmitter or zigbee radioan RFID tag or tiny geocache
Throwies -- UV LEDs, a battery, and a magnet inside a neon straw
spare pencil leads
jeweler's saw blades
X-acto or craft knife blades
baking soda -- used with super glue to fill gaps
hard drive screws, cable tied to the inside of the case 
sharp tools or drill bits
 
HOW TO DO IT:

- Go out for boba and swipe some extra straws , or pay $2 for dozens at your local asian market or online.

- Put aluminum foil over and under the straw to prevent it from sticking.

- Press the straw end with your heating tool, soldering iron, or whatever, moving around until the plastic fuses completely shut.

- You only need to seal once straight across, but more is better.

Improvise if no soldering iron is handy:

  - Fold the end over and insert it into a short piece of straw or a pen cap
  - Close it with the smallest size of binder clip
  - Iron it shut with a light bulb, hot butterknife, or the lid of a Zippo lighter 
  - Melt it with a clothes iron or hair curling iron
  - Heat (or burn) the end with a lighter and squash it flat under a water glass
  - When melting the end, use foil or wax paper to avoid sticking or burning.

You could get all fancy-pants with it too:

  - Make the melted tab longer, and punch a hole for an eyelet, rope, cable tie, keyring, or carabiner to pass through
  - Add a rare earth magnet and stick it to a fridge or toolbox
  - Make a laminated nametag or cable label by ironing in a strip of paper