Starting a New Habit

So - my friend on another blog has challenged those of us that want to make a change to attempt it for the next 21 days. Today was day 1. Mine didn't quite go as planned. I'm wanting to do some form of exercise for 30 min each day (minus weekends - I need time off). Today was supposed to be a 2 mile run. The weather was crummy all day - snowy and wet, but not terribly cold. My running partner has switched jobs and has limited time and wants to do a different program that is indoors. So - we aren't planning on running outside together until spring. I was going solo tonight. Todd told me it was pretty cold so I got all my gear on and went out. I'm not sure I even made it 1/4 mile. It wasn't the cold...the wet pavement froze and there was a sheen of ice, my feet kept slipping. I probably could have done it, but I was afraid with the altered gait I would hurt myself. So I came home. Day one - bust! Trying again tomorrow. Heading to the Y for some time on a bike and with the weight machines. (providing the gunk isn't pouring out of Veronica's nose - today wasn't so bad) Anyone else want to jump on the 21 day habit? Giving up something, trying to add something, let's support each other.