I saw these at LL Bean. They are clever enough to include a ditty bag so you can both use the water bottle and carry the contents, although they seem kind of gimmicky to me, and the contents aren't of the greatest quality. They have a bunch of them -- Fitness in a Bottle (biner, pedometer, sunscreen, lip balm, first aid kit and stuff sack), Outdoor Survival in a Bottle (whistle, compass, shake flashlight, small knife, emergency blanket, poncho, duct tape, first-aid kit, waterproof matches, biner, carry bag), Paddler in a Bottle (compass/whistle/waterproof match case, light sticks, emergency blanket, poncho, first aid kit, sunscreen), Auto Aid in a Bottle (shake flashlight, knife, screwdriver, tire gauge, safety flasher, reflective vest).

...and if all of that surviving is stressing you out, you can go for the Toblerone in a Bottle (1 lb. of Toblerone chocolate), or the Travel Spa in a Bottle (shower gel, shampoo, conditioner, soap, razor, shaving cream, lotion, toothbrush, toothpaste, mouthwash, bath salts, vanity kit, mending kit, stuff sack).

How do I repair my de-magnetized compass?
If your compass becomes demagnetized (points in the wrong direction), place the South Pole of a magnet directly on top of the compass needle. Slowly slide the bar magnet along the red side of the needle, toward the pointed end, and then down the side of the compass. Pull the magnet away and your compass is re-magnetized.

Is there a simple way to tell which end of a magnet is the north pole?
Both poles of a magnet look the same. However, if you place a compass near a magnet, the needle that normally points toward the north pole of the earth moves in the direction of the magnet’s south pole.