I use Seirus Cat Tracks which I got at REI
http://www.rei.com/product/197509.htm. It's small enough to fold into your pants pockets. Just make sure to shake 'em to get pebbles and ice off so they don't end up in your pockets. I think it's a great device especially if you have your boots canted. I wear it even in the lodge and put them away just before I click in. I figure that with all the money I spend on my boots, this is a good investment.