I ride on the wrong side of the road on the bike lane on my way to campus because making a left turn is a b1tch. I'll go to the right side carefully and slowly. I think it is okay to go the wrong way if there is a bike lane, but if it is just a plain street then you definitely have to go with the flow of traffic. When riding the wrong way in a bike lane, I always stay to the right when other bikes are coming at me (which hardly ever happens) so that they know which way to pass.
fyi, I only do this for maybe half a block. Which, I think, is acceptable.