-Use in underwater camera casings
Underwater camera casings are great fun, but even if stray moisture and condensation don't ruin your camera, they can fog or streak across your lens. Fight this by stashing a packet or two of silica gel in the underwater casing, along with the camera.
-Toss them in your toolbox to keep your tools free of oxidation
"I am a line mechanic for Delta Airlines. We do all our work here outside since we don't have a hangar. So when an aircraft arrives with maintenance issues I have to wheel my tools outside, leaving them vulnerable to weather, and sometimes my toolbox gets filled with snow or rain. I have found that if I put two desiccant packs per drawer in my toolbox, it is just enough to dry them out and keep my tools from oxidation."
-Dry out a wet cell phone
This one's an old favorite. If your phone becomes the unfortunate victim of a spill or swim, you can still rescue it—you just need to act fast. Remove the battery and any memory cards from the phone, then toss it in a bowl filled with silica gel packets (dry rice will work, too, in a pinch). Leave it there at least overnight before powering it on again.
-Keep engines dry while in storage
"I fly ultralight aircraft and use silica gel in my engines (snowmobile engines converted for aircraft use). I put the gel in old plastic 35-mm film canisters. I drill holes in the canisters smaller than the beads so they don't come out, and I put one inside each carburetor intake to help keep moisture out of the engine while it is in storage during the winter. This helps keep the bearings from pitting and the internal parts of the engine from rusting. Snowmobilers could benefit from this during the summer while their sleds are not being used. "
-Extend the life of razor blades
"It is understood that oxidation on razor blades causes premature dulling. I keep a Tupperware half full of silica gel in my medicine cabinet. After each shave, I blot any residual water off the blade and store the razor in the Tupperware with the silica gel."
-Fight camera condensation
If you're taking your camera out into the cold, it can face serious condensation when you bring it back into a warm room. Remove the battery and memory card, and place the camera in a bowl of silica gel to suck up the moisture.
-Dry out wet fishing flies
"Being an avid fly fisherman, I use silica to dry out my flies when fishing on a favorite stream. I crush or ground the silica into powder form, then place it in a film canister. When my fly becomes waterlogged, I place it into the canister, put the cap on, shake it for a bit, and voilà—my fly is dry again."
-Create a dry travel bag
This one's for the road warriors. Toss a few packets of silica into a Ziplock bag to make an instant travel gadget bag, with enough water-fighting ability to withstand accidental luggage spills.