It's 2014 and Cash is still KING

One of the most important tips (beyond your passport and tickets) I can give you about traveling internationally is to have a plan for cash.  In this day and age where I can "charge" almost everything in my normal daily life, when I travel internationally, I find myself in situations where credit cards are not accepted.  Specifically on my last international trip (Brazi), here is a list of items I could only pay for
in cash.

1. Taxi
2. Public bus transportation
3. Bottled Water / convenience store purchases
4. Bed & Breakfast accommodations (I stayed at the #1 ranked TripAdvisor B&B in Rio and they only accepted cash).  Most hotels will accept credit cards as a valid form of payment.
5. Kanga vendors (vendors selling beach wraps and food)
6. Tips
7. Most restaurants accepted credit cards, but some smaller places only accepted cash.
8. Generally speaking, the smaller the amount of money needed, the more likelyhood that only cash will be accepted.

Cambodia

Cambodia was a very interesting country as they are literally a young country.  Their main form of currency is the US Dollar.  An ATM machine in Cambodia will spit out US dollar bills.
When we entered Cambodia, there was a mix-up in our tour destination and (long story short), we ended up having to buy a last minute plane ticket from Phnom Penh to Siam Reap.  The Cambodian airline only accepted CASH for this last minute plane ticket. 

Local Currency

Assuming the country you are visiting does not accept your home country currency (i.e. US Dollars) as their main form of currency, you will need to exchange your money for foreign currency.  There are a few methods to do this.

1. Contact a local money exchange agent in your local area. In the US, you can visit an American Express office to obtain foreign currency.
2. Contact your local bank for foreign currency.  This usually requires you to fill out some paperwork, pay a processing fee and/or make an appointment with your local bank or go to your bank's headquarters to obtain your needed currency.  This method usually does not net you the best exchange rate either.
3. Bring your local currency (and/or travelers checks) and exchange cash at the airport or any money exchange office.  Many countries I have visited have money exchange stores in strip malls.  Airport exchange offices are notorious for poor exchange rates.  Note about travelers checks: With technology advancement and rampant fraud, travelers checks are not quite as popular as they were 15-20 years ago.
4. ATM - My most preferred method for obtaining local currency is using the local ATM.  There are a few caveats to using a foreign ATM and safety concerns, but all in all it is a standard practice these days.  If you jump into a cab without any cash, most cab drivers will be happy to take you to the nearest ATM.

Security

Thus, you may need to carry around large amounts of cash during your international travels.  For security, I recommend keeping cash in a money belt tucked inside your clothes. 

 

After your trip

If you find yourself with foreign currency cash after your trip, you have a few choices.  Best case scenario, you budget yourself perfectly and have no cash left, otherwise...

1. Keep the currency for your next trip.
2. Sell the currency to a friend or someone you know who is about to go there.
3. Take it to your bank and deposit it into your account.  The exchange rate will not be the most ideal but it is the most convenient method.