Slate has an interesting article by Steven Landsburg about the minimum wage. The first half debunks the common argument that it causes unemployment. He goes on to argue that the minimum wage places an unfair burden on a small minority, and we would do better to instead focus on welfare funded by all taxpayers (apparently the US has something called 'EITC' to this effect).
For some disagreement over that second point, see Majikthise and Brad DeLong.
Update: Crooked Timber has a good overview of the matter.