Money, money, money...

The currency of Vietnam is the Vietnamese Dong, abbreviated as VND, and the approx exchange rate is US$1 = 21,000, AU$1 = 21,500, £1 = 31,000 VND
For the latest daily rates check out - http://www.vietcombank.com.vn/en/exchange%20rate.asp

So that's quite a lot of zeros to deal with and yes, your mathematics is correct, you will all become instant millionaires upon landing in Saigon - congratulations!

Notes in circulation include 1000, 2000, 5000 which are usually quite old and worn with a paper like feel. Larger value, newer notes are made of plastic (same place they make Aus currency) and consist of 10000, 20000, 50000, 100000, 200000 and 500000 check out the image below.

I'd recommend bringing US$100 dollars with you - a $50, 3 x $10, 4 x $5. That's enough to pay for a visa on arrival and your cab to your hotel, which should be between 150,000-200,000VND = $10

For the rest of your spending money, bring your ATM card and/or some GBP or Aus dollars with you which you will be able to change for VND at one of the local exchanges, click here for locations. Make sure the notes you bring are new, if they look like they've been through a washing machine they will not be accepted by the exchange.

There are lots of ATM's in HCMC, but you'll be charged an overseas withdrawal fee and possibly a local fee too - check with your bank. They often have a maximum limit on fees, for example my CBA account charges $2 on overseas withdrawals, you can take out up to $500 from their branches in HCMC, with no local fees! ANZ are in Vietnam too, plus HSBC however they operate as different companies and are not all connected to the same banking system, frustrating...

Things are generally pretty cheap in Vietnam, they don't have MacDonald's so I can't use the Big Mac index, but a glass of beer is between 30-50,000VND (approx $2), a main course at a reasonably priced restaurant around 150,000VND (approx $8) and the average cost of a 10 min cab ride in the CBD 60,000VND (approx $3).

You can also get 5 star food for 4 star prices, so many people including myself, go to the slightly more expensive places. The cost will be the same as you'd pay at home for a average meal in an average restaurant, but the quality of the food will be some of the best you've had. Saigon really is a foodies paradise!

One word of warning the 20,000VND note (blue) and 500,000VND look quite similar (light blue) but their value is radically different - be sure you don't mix them up.