Winter Cycling - Super lightweight windstopper shoe covers

Any recommendations? Doesn't have to insulate completely; it needs to repel lots of wind. Another requirement is they would fit in a single jersey pocket, or a small pocket mounted at the bottom of the seat (think Assos arm and leg warmers form factor). I have large neoprene shoe covers, but not what I'm pursuing...since cycling shoes are all made out of mesh, occasional windproof insulation can come in quite handy. I'm almost tempted to sew something together with nylon and such, geared for descending from high altitude at very fast speeds.

I use a pair of packcloth like covers in wet or cold weather, from MEC, available in lots of places. Not very pretty or aerodynamic, but does the job.

If you're looking for something Goretex or Windstopper, one of the first places to look is Gore Bikewear. It's usually good stuff, but also hella expensive.

For a solution that's light and easily carryable that doesn't break the bank you could get the windstopper toe protector - it would cover the front of the shoe where the vents are (Oxygen Toe Protector - $30 retail). Cheaper and smaller:
http://www.gorebikewear.com/remote/Satellite/PROD_FOXTOE?landingid=1208436871979A

They also make a full windstopper shoe cover, but it's pricey and bigger (Oxygen light overshoe - $70 retail):
http://www.gorebikewear.com/remote/Satellite/PROD_FLOXYG?landingid=1208436871979A

But if I was considering paying $70 for the full cover, I'd just get the full goretex version for another $20 and have something that's both waterproof and windproof. I've got a pair and they're real decent, although I balked at the price but I found them on end-of-winter clearance for $62 (City Overshoe - $90 retail):
http://www.gorebikewear.com/remote/Satellite/PROD_FCITYF?landingid=1208436871979A

plastic bags?

Being that I am a Fred, I used my Herman survivors with wool socks. In all fairness the coldest that I rode in was 0 degrees. I also had NEOS overshoes but, I never felt the need to use them. I am/was not comfortable with riding in below zero weather.