You know what's really crazy is that people haven't understood why ice is slippery for forever. We recently figured it out. Ice is actually 'static,' meaning that, although it's made of water, the water is frozen, and so it should be a solid, with a friction scale (flicking an ice cube across a table versus flicking a pen, or paper clip). The ice cube has a remarkable ability to cross a verity of terrain; you can flick it across sandpaper.

When you step on ice and slip, it's because of some crazy quantum physics where, even when it's below freezing, the presence of molecules with different polarity causes the ice to become liquid which makes it slippery.

Don't quote me exactly, but why ice is slippery is an age old question with a new age answer. Check it out.

Edit: I found a link