Phil, look for the kind of toe-warmers that have an adhesive patch on one side. You can just smack 'em on the top or bottom of your socks (whatever works best for you) and they'll stay in place pretty well. Be sure to shake them well before use. Like I said, they're not the best if you have to walk around much since they can be blister starters, but they're great for sitting in a blind or boat.
Matt, I use a small portable wood stove in a parachute cloth tipi during late season hunts and backcountry ski trips. I've awakened to the smell of burning dog hair on several occasions since he just can't resist hunkering down as close to the fire as possible.