Most people need a visa for Laos but getting one is easy.
The cost is $35-50 U.S. for a 1 month visa, depending on what passport you hold.
In many cases you can get a visa for Laos at airports on arrival and at land borders. As of early 2010, this now includes the Dom Kralor land crossing into Laos from Cambodia. According to Zoe and Paul, a couple travelling by bus and bicycle in the region, the visa at the Cambodian-Lao border costs $35 for UK and U.S. citizens and $42 for Canadians, payable in U.S. funds.
“This is cheaper than the embassy in Phnom Penh which is a rip off. An American on the bus got his visa same day in Phnom Penh and they charged him a hefty $65 U.S.! Needless to say, had he known it was possible to get a visa at the border, he would have done so. So spread the word!”
At the border, Lao guards often ask for an extra $1 U.S. per passport for the entry stamp. This is annoying but unavoidable. They won’t even get out of their hammock unless you pay up. We tried very hard not to pay and this only resulted in the guard returning to his hammock until we got out a $1 bill and waved it around in front of his face.
The standard tourist visa is issued for 30 days and can be extended for up to a month at a cost of $2 U.S. a day in Vientiane. The visa renewals are done within a day. You can also get agencies in Vang Vieng or Luang Prabang to send your passport back to the capital and renew the visa for you. If you really plan to cycle all of Laos from top to bottom, getting a 60 day tourist visa in the first place may well be cheaper.