I use a snowboard jacket. It has pit vents and pretty thin insulation, goes over my hips and allows a full range of motion. I agree about the dress shirts though, it's easier to take some to work and have them waiting for you there.
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Genesis 49:16-17
"Well, well!" said Holmes, impatiently. "A good cyclist does not need a high road. The moor is intersected with paths and the moon is at the full."