It's slippery outside because of the ice and you need to get somewhere. Slip-on spikes like the Nordic Mini may do a good enough job to get you there. But to be ready on the streets when there is no ice yet without having more stuff in your pockets you need something a bit more ingenious like Meindl Spikes Boots. They look like normal winter boots but when you turn the dial in the heel area, spikes will discharge from the sole, ready to take on the icy streets. The spikes have three points each and are made from tungsten carbide, which is twice as dense as steel and almost as hard as diamond. The boot itself has breathable, waterproof Gore-Tex lining with luxurious lambskin and abrasion-resistant Tec Vision rubber tread sole.
Check out Meindl's site for availability.