Best commuting jackets for winter?

[Melalvai]

I'm about the layers, too. I just put on two jackets.
If it's *seriously* cold (which is going to be a different temp for different people) I get on the trainer for six minutes before going out. Then I don't even have that "cold before you get warm" thing, tho' if you're at the subway in 10-15 minutes you're not going to get *that* cold.

I do jumping jacks. But for 20-30F, that's not usually necessary. That's for <20F, for me.