Just back from a 1 week visit from BKK to Laos. Flew into Vientiane (Lao Air) and returned from Luang Prabang (Bangkok Air). My entry experience as per Hungdonger. V easy provided you have USD. I'm told they prefer/insist on brand new notes. Its a great time to visit since relatively quiet (few China tourists). A couple of observations from my visit. LP is much more interesting imo than Vientiane but it depends on what you like. V is a sleepy capital that has a certain charm but LP is a major tourist destination. Highlight for me in LP (among many) was the one day river trip organised by Manifa Travel (check out on google maps) - excellent in every respect. I took the new China-Laos high speed train from V to LP; 2 hours compared to 9-10h bus journey or a 1 hr flight. Great views of the landscape compared to the plane, and you can stop over in Van Viang, a sort of adrenalin activities place for backpackers. Getting ticket for the train is not straightforward and requires a separate thread due to the complexity. My hotel sorted everything but not all offer this service.