Currency in Vietnam
 

From what I've read, both USD and VND are accepted and I'm just wondering if I should take some small US bills along with exhanging money while there for two weeks?

Some places you can pay in USD but remember you are at the mercy of their exchange rate! Some small bills is a great idea but its super easy to get cash from the many ATMs. (i hadn't any VND on me when i landed in Hanoi but there was an ATM right outside arrivals. (although i did actually tip the cabbie in $$)

USD are accepted in some places, but generally they give you change in their native currency. Just a tip, Capital One has a credit card that doesn't charge a fee for foreign transactions and the Macy's Visa card only charges 1%. This can be really helpful as many merchants will only accept a credit card if you agree to pay their 3% merchant fee. If your regular card charges you 3% also, you end up paying a whopping 6%!

Generally, you save money by using VND and the ATM's. USD is accepted, but not needed. I find my debit card most useful to get cash in VND from an ATM, and credit card (Capital One) for large purchases or when I'm just too lazy to trek down to an ATM, but credit cards are not accepted here for small purchases. Most useful are small denomination VND bills (20,000VND) to pay cab drivers who lie that they carry no change - ONLY USE MAI LINH CABS - VERY IMPORTANT!

Thanks everyone. Aren't there a couple more cab companies that are ok to use also?

Hanoi Taxis and CP are also good.