Baby it's cold outside! Bundling up in lots of layers is fine, but not so great when you need to move around a lot, say snowboarding or skiing. Each layer adds more bulk and less flexibility.
How about packing some heat?
I've been trying out a sample of a vest from Ardica Technologies that is definitely unique. The Ardica Moshi System provides your own private heater for up to 8 hours on the low setting, or three hours on high. Basically it's a thin battery-powered heater that goes in a flap resting against your back, between the shoulder blades. You recharge it before you go and then control it through a lighted insigna on your chest, Star Trek style. In my tests the heater made a major difference, keeping me toasty on long walks in sub-freezing weather. It's light enough and thin enough that it wasn't a nuisance either.
But wait, there's more! The system also has a USB plug that allows you to charge up your iPod while you are on the move. Unfortunately that plug is situated in a side pocket rather than the one close to your ears where there is a slot to put your earphones through. So you either listen or charge, but not both. However, you can also use it to charge your cell phone or anything that has either a USB plug or an adapter with one. Other commercial jackets on the way will probably have multiple linked batteries and charging ports situated differently.
This is no thrown-together piece of technology. You can thank the U.S. government for laying out the millions in research grant dollars it took to develop it all. You see, soldiers don't like to be cold either.
The only problem is, the marketing has gotten ahead of the actual availability. You can't buy it from the Ardica website, so apparently I'm special to have gotten this loaner. Mountain Hardwear is going to put out a jacket equipped to use the Ardica heating system, but not until the fall of '09. Assume this will add a chunk of change to the price of a jacket as well, anywhere from $150 to $200. (Yet as it stands now, there's only a one year warranty.) But hey, my wife would have gladly paid that last time we spent a long weekend skiing in the blustery cold.