After being to the north of Vietnam we decided to have a look at the south too. We started the journey with a couple of days in Ho Chi Minh. The city itself is not worth the trip. There is not much going on. But you can find good accomodation and restaurants there and then book in on some day trips.
We stayed in the backpacker area in district 1. Hotel An An is a cheap but fairly clean place. http://www.ananhotel.vn/html/
And you just have to walk a few corners to find nice restaurants and bars. We booked a tour to the Mekong Delta (around 10 US) and a half day trip (8 US) to the Cu Chi tunnels left over from the war with the US. http://wikitravel.org/en/Cu_ChiYou can crawl the tunnels but it's quite discomforting as it is pitch dark and space and air are limited down there. But it's interesting to see how the local people survived in there. 
Our next destination was Nha Trang about 350 km up north. It took us around 10 hours to get there by public bus transport. But the journey was nice as you see quite some interesting scenery. And we had sleeping seats so that there was enough space to make ourselves comfortable. Nha Trang itself is a nice beach town. http://wikitravel.org/en/Nha_Trang
You will find lot's of restaurants, bars and hotels. And it's very reasonable. For about 20 US you can get a nice clean room with roof terrace. Just walk around and ask in the hotel. We changed hotels three times and never had a problem to find a new place. The atmosphere in Nha Trang is relaxed and the food is so good even in the smallest restaurant.
From Nha Trang we booked a tour to Dalat which is located in the mountains. http://wikitravel.org/en/Dalat
On the way to Dalat we made the mistake to take the tourist bus which took us almost the whole day to get there riding as fast as 30 km/h. But on the way back we booked the local mini bus which was quite quick and took only about 4 hours. The scenery on the way to Dalat is very beautiful. You climb up the mountains and you feel more like being somewhere in France with all the pine trees around you. We stayed there 
only for one night so we had to book a private tour for the morning of the next day. It cost us 30 US which is a little bit more expensive than the other tours we had done before but it was worth every cent. You can plan the trip very individually and they take care of what you like most. So we had a look at the coffee plantations and the silk and greenhouse farms, headed to a waterfall and had tea in a local house where they were growing mushrooms. Our tour guide was a very nice guy who liked to discuss all sorts of topics even corruption and Vietnam's difficult relationship with 
China.
only for one night so we had to book a private tour for the morning of the next day. It cost us 30 US which is a little bit more expensive than the other tours we had done before but it was worth every cent. You can plan the trip very individually and they take care of what you like most. So we had a look at the coffee plantations and the silk and greenhouse farms, headed to a waterfall and had tea in a local house where they were growing mushrooms. Our tour guide was a very nice guy who liked to discuss all sorts of topics even corruption and Vietnam's difficult relationship with China. Back in Nha Trang we booked the night train to Ho Chi Minh for the next day. It took about 6 hours and we had a good sleep even though it might look a bit dodgy to somebody coming from the Western hemisphere. But it was good fun.