The snow and ice has been hanging around far too long this year, and normally I wouldn't even venture out; but Tommo blogged about carrying Kahtoola micro spikes for running in and as I was climbing the walls desperate to get a few miles in, I bought a set.
They are superb.
The pair fit in the palm of your hand, or a stuff sack.
Have spikes on the forefoot and heel.
...and they give you serious grip.
I've put about 20 miles on them and it's as if they're not there, and there's no snow/ice around. They don't slip or flap, take about a minute to put on/off and they just are what they are and do what they're supposed to do.
Just this morning I've seen some blogs about putting screws into the sole of your shoe to give you the same effect. What a waste of a running shoe! These spikes are serious kit and will probably last for decades.