I have just bumped my winter tires up to 38psi as most roads are bone dry now, and snow is just about over and done with for the season. 30psi for traction when there's snow on the roads though.
Summer - I have my 255/50's at about 40-42psi, it's the only way to run IMHO. Too soft a tire even though it gives good traction on launches - tends to 'fold' over on harsh turns. I prefer a bit of a skip/slide when cornering hard then the car trying to roll over. Also there is the benefit of easier burnouts.
:L