Viang Vieng is a backpacker town in Laos, with all the Thai type backpacker amenities - the bars show videos and sell lots of western food. Internet cafes etc are everywhere!
The main tourist activites, apart from sitting in a bar drinking all day are either kayaking and caving or tubing, both down the Mekong river. I chose the kayaking, which went to a couple of caves and down the stream that is the Mekong in the wet season! I loved it! This gives a chance to see how locals live along the river - as the river is used for everything - from washing themsleves or their teeth to their motorbikes and buses!! Most of these tours seemed to be 10USD for a day and well worth it!