I came here about 3 years ago to train some iPhone devs for a friend's company. Ended up making a lot of friends out here in the process. Even though it's mostly an illusion, there is a certain sense of freedom here. It's also the safest of the SE Asian countries, imho.

I live in a more upscale part of Saigon, so my rent isn't typical. But compared to what I was paying in NYC, it's not a lot. I pay $700 for a 2 bedroom in a high rise, about $100 for electricity. I have fiber internet, 40mbps, which is about $75 a month. 3G on my phone is about $5-10 a month. The sum of all of that is almost a quarter of what I was paying in NYC every month.

I'm living in Vietnam as well. Dalat is up in the mountains, has cool weather all year round, and is much cheaper than Saigon. A room for rent is about $100 per month, a Banh Mi roll is about 10 cents. The main disadvantage of living up there is that there is no programmer community. But, if you just need to sit in a room and code and save money, it's perfect! Also, the people are super friendly. :-) Best experience of my life.