PS Opospa, we can no longer get a new visa by just crossing a border and coming back again. Now we must apply for an extension at an immigration office. It wouldnt cost 20 US dollars a day. More like 20 US dollars for 10 days. But I have not checked to find out exactly how much so Kaypt can check that on the internet.
Oh, but i saw some Farangs doing that at the Poipet immigration. But i never need a visa since i got my Thai ID.
i did it at the burma border down south back in august. there are plenty of visa runs advertised in all the travel agents down south!