A lifesaver I have found for commuting is Downy Wrinkle Releaser. I leave some in my locker at work. You spray it on your clothes when you get to work, tug at your clothes, and voila! Wrinkles are removed. I've been using the stuff for the past 3 years and swear by it. Also, I found that if I roll my clothes before putting them in my panniers rather than folding them, it will reduce the number of wrinkles. I usually throw them into the dryer while I'm packing my bags in the morning to reduce the wrinkles.