There's always something to do and see, from the monks seeking alms at dawn, to bargaining at the open air Hmong markets, to watching women embroidering and weaving, or just to wander slowly along the side streets and through the temples.
The Lao are great party people and there's always a 'do' going on somewhere in town to which people will generously invite you. The Lao are perhaps the nicest mannered people in the world.
For travellers from the west it's like stepping back into another age where children can play out in the street, people are always ready for a chat and even the traffic moves slowly. [You'll find time moves in a different way here to the rest of the world.]
The best way to see the town is either on foot or by bicycle. To see the countryside you can rent a boat and travel the Mekong or go by tuk-tuk to some of the remoter villages. These are real villages, not just some people sitting around in national costume waiting for tourists to turn up.