Last week I saw a photo from the California Highway Patrol office up in snowy Truckee that reminded me of some very interesting traction-augmenting devices that work like zip ties. They're called "tire zip ties" or something similar, and they're basically just extra large zip ties with a special gripping area that you fit around your tires for better traction on snow, ice, and mud.
They're a great alternative to regular snow chains, especially for those who don't want to deal with the hassle and expense of fitting them. They're also much easier to use, as you simply loosen the ends of a few of them and slip them over the tire's tread. The traction they provide is fairly limited, though, and they're probably best used for getting stuck cars out of the mud or snow rather than driving for extended periods at highway speeds.
Another option is the Zip Grip Go, a set of emergency tire traction aids that install in minutes and don't require any tools. They're also easy to keep in your trunk, a glove box, or suit case for emergencies. They don't have the durability of chains, but they'll do the trick in most situations and are very lightweight.
Of course, zip ties have other uses as well, including making first aid slings, tying things together, and so on. They're a cheap modern marvel and are found in most survival kits, so picking up a few sets is always a good idea.