Well, via dialup (the most popular method in nepal) i doubt u can get much done. There are other options though: cable and wireless (a direct radio link from the ISP to your place). These will be much faster and more reliable than dialup for sure, but still you wont get high speed as you are used to in the US.  Through the cable connection they market it as a 88kbps (kilo BIT) connection ... so u'll download at about 11 kbps (kilo BYTE) : and that too it costs about Rs. 6K a month. Even with wireless the cost comes out to the same for similar speeds. I think there are some providers who promise you a 124kbps downlink as well, dunno about the pricing on that. I would say you will be able to VPN and get some work done; but I wouldn't suggest heavily relying on it. Have some sort of backup plan ready where you can work offline. VOIP should be fine. I haven't tried it with the vonage service, but skype over the 88kbps line works pretty well.

Hope that helps
~nkc