I have done that kind of thing too, now and again, but I am extremely wary when I do it.

One thing I really, really hate and which is common around here, is when someone riding down a two way street with bike lanes, crosses to the other side before the corner, and rides around the corner in the wrong side's bike lane. People do this, I think, because they are afraid to ride through the intersection. They don't pay attention to the fact that they are coming around a corner the wrong way, blind, into traffic--both bikes and cars--that often can't even see them until they round the corner. It drives me nuts.

There is one particular corner where I see it almost every day--Navy and Flushing in Brooklyn. People riding South on Navy will cross into the Northbound lane and turn left on Flushing. They will then ride the wrong way in the bike lane until they feel like they can cross Flushing. There is a construction fence at the corner, and has been for a year or more, so you can't really see jack until you're around it. Very stupid.