Border Crossing
Looks pretty official, huh? For those of you traveling to Cambodia or Laos: As of the date I write this, at the border crossing you can get a visa upon entry when traveling from Laos into Cambodia, but not vice versa. I am sure things will change soon and am pretty sure flashing a little extra money could get it done as well, but they claim heading north from Cambodia into Laos, you can't get one. You can always get one in advance very easily for any of these SE Asian countries before entry though.