I don't live where chains are normally (or legally) required, but there certainly have been times when a little more traction would have been nice.
I stumbled upon this video that shows some alternatives to chains. (Warning: it's 20 minutes long)
The Snow Socks look interesting; there's even a similar product made by Michelin, which I guess gives the concept some credibility. There are also individual "traction strips" that go through the wheel and wrap around the tire perpendicular to the treads.
My concern with the sock type is that all the installation instructions seem to indicate that you need to move vehicle forward just a bit to finish the installation. Maybe just rolling the *wheel* itself, i.e. slipping it a 1/4 turn on the ice, is enough, assuming you don't spin the sock right off of the tire. Of course, everything works perfectly in the video.
Has anyone tried any of the "chain alternatives", especially to get out of a stuck situation where the tires just spin and/or slide sideways?