You'll want a way to conceal your cash and documents. We found money belts at Target for $6.99.

A small quick-drying travel towel is a great addition to your go-bag. They don't take up a lot of space in your bag, don't weigh very much and can also be used for backpacking trips.

Multi-tool with pliers. You can go for cheaper brands or models, but you want something heavy duty enough to work in a survival situation.

Survival whistle

MREs = Meals Ready to Eat - Each meal should contain a heater so you can eat your ready meal hot. You can buy military MREs or civilian MREs. Two good brands for civilian MREs are Sure Pak and a-Pack. MREs usually have a shelf-life of five years.

At least one person in your travel group should have a camp axe.

An LED headlamp is not an essential, but it's a lot easier to walk in the dark with a headlamp than when holding a flashlight. There are many different brands and varieties. You'll want something that's not very bulky and provides at least 50 hours of light for one set of batteries.

Make sure you have a way to purify water. Water purification tablets are a lot cheaper than full-size water filters, although the water won't taste great.

Don't forget sanitation. Have at least one roll per person in a plastic bag.

For women, you should have feminine hygiene supplies in your go bag. An alternative to bulky tampons and pads is a reusable menstrual cup.