If I wasn't hallucinating, I do believe that Laos no longer requires a visa for those from my country (i.e. Singapore). That might have happened last year, though information is scarce and the Lao embassy NEVER picks up the phone.
I'm sure this will be honoured if I fly in to Laos, but what are the chances that they'll insist on me getting one anyway, if I cross the land borders? That was my experience in Cambodia, when I crossed at Koh Kong and even though I didn't require a visa they made me buy one anyway along with everyone else.
You should be fine -- the Ko Kong is a particulary problematic crossing for that kind of thing.
In the unlikely situation they they do insist you have a visa -- you can just get one -- the Lao visa on arrival is now 30 days.