At both the international and domestic terminals there is a taxi counter. Here you prepay your journey and are assigned a driver. The standard rates to the city are US$7, 8 or US$9 – depending how far you are going. This is displayed on the counter.
Alternatively you can walk out to the main road and flag down a tuk tuk. The airport terminal is 200-300m from a busy main road, with plenty of traffic. A tuk-tuk to the centre will depend on your negotiating skills but should be LAK10,000/15,000 but if you have no local currency it will be a couple of USD. A rule of thumb conversion rate in Laos is 8000 kip to the dollar. Of course it will be a breezy ride.
Public buses do go along this road and the set fare is 6,000 kip – prices have recently increased by about 1,000 kip on most routes due to inflation (2011)