Yoy can rent bikes for not more than 10.000 Kip (less than 1 US $) for a whole day. We hired them in Phounsab Guesthouse but the quelity could be better.
We're too tall for these Asian bikes with their small frames.
So I have heard that they have not had a good track record but the flight was 45 minutes and the alternative was to drive on a windy road that can make most people sick to their stomach. The ticket was like $100 from the capital there.
Flights within Laos are fairly cheap but you miss the beauty of the countryside. Luang Prabang was $55 US and Xieng Khouang was $35. Visa-on-Arrival (good for a 15 day entry permit stamp only) is available at the airport - price is USD30 (payable in USD).
The Airport is on Airport Road which is across the Nam Khan River 5 km from town. You can hire a moto or taxi to take you to town.
We rode on a speed boat down the Mekong River from Huay Xai to Luang Prabang, the boat had 10 people on board and was very, very cramped and also loud. The trip took 6 hours and we were stiff and sore by the time we arrived, but i must admit i enjoyed it. Next time i'll catch the slow boat though (this take 2 days). We paid 1200 baht at Chiang Khong, Thailand (across the river from Huay Xai) and despite what some publications say, Loa visas are available on arrival at Huay Xai
Here we are getting ready for the first leg of the journey. We tried not to think of the people who were killed when their boats hit rocks in a shallow part of the river the previous dry season.
The last leg of our trip was by slow boat across the Mekong to the Thai border control checkpoint. We were happy and relieved that we had made it. Laos was a great adventure!
Overall, boats were the best mode of transportation. Make sure you have enough time on your trip to use them.