Myosmith

I just got a pair of Schwalbe Marathon Winters in 700 x 40 and put them on my Plan B hybrid that I have been using as a winter bike. I had been riding with hybrid 700 x 28 tires which were fine for the occasional slippery patch, but the roads for the past couple of weeks have been solid snow pack and/or ice. I haven't seen pavement except in the lane tracks for quite a while. Big difference, I took a short ride to try them out as, by the time I got home from work it was already getting close to dark. I did about a half hour on residential streets at 10-12 mph with lots of stops and turns and was very pleased. I never even felt close to breaking traction. Even when I went through some rough stuff on purpose, the control was excellent. When I have more time (tomorrow I hope) I'll take them out for a real test, but even if all I do is tool around at 12-15 mph its a whole lot better than staying indoors.

sknhgy 

I have Nokian Mount and Ground tires on my 26" Rockhopper. It is a joy to ride on ice and hardpacked snow. Folks who don't ride in the winter don't know what they are missing.

Leebo

Try riding on some frozen ponds, awesome.

scoatw

I ride on Nokian Extreme 294's. They will go thru anything. I've used them on dirt riding the MTB trails. And I've ridden them on glare ice. Which is what they were designed for. I've ridden across empty parking lots after an ice storm. And the parking lot looks like a frozen lake. I rode across it doing big sharp S turns, trying to get the front tire to slip. And it just wouldn't slip out from under me. Maybe a little bit once or twice. It's grip on ice is something else. But its given me confidence that no matter how bad the roads are. The Nokians will be able to handle it. They're good up to about 4-6 inches of snow. Anything more than that and you're probably walking.
And you're right. Folks who don't ride in the winter don't know what they are missing. Whole different world out there.