Best Sim for a week in Vietnam?
 

I'm guessing none of the SIMS I use in the EU are going to get me good rates in Vietnam. I'll be there for one week and in Hong Kong for 12 hours. Recommendations appreciated.

Maybe you want to play with the new Knowroaming.com solution.
They have 15ct/min to call from vietnam to US, 1 USD/MB data in Vietnam and
11ct/min / 0.2 USD/MB from Hongkong.

piranha mobile has
24ct/min to call from Vietnam and 1.12USD/MB data,
14ct/min to call from Hongkong and 13ct/MB for data.

I was told that vietnamese SIM cards are very cheap and can also be purchased at the arrivals section on the airports.

If you know someone who would add a line to their acct. on T-Mobile U.S., temporarily for $10/mo. - you would have unlimited text and data and 20¢./min. calling. Vietnam is one of their 120 "free" roaming countries. I did that for a cousin who went to Europe.