The other thread about wind reminded of this. I always have felt that living east of your workplace is the most ideal when it comes to bike commuting. It is much safer to ride with the sun at your back both directions than in front of you both directions. That way drivers coming up on you will never be blinded by a sunrise or sunset. The afternoon winds from the west that occur in much of the country are also a benefit, giving you a tailwind on the way home instead of a headwind.