Chet,
How do you want to use it, and how much do you want to spend? We have folks with USB webcams looking out the window (like the SkyCam image on my web page) and wireless weatherproof IP cameras (my GardenCam image) and lots more. Some have used USB webcams in heated enclosures outdoors. Costs vary from $30-$500, or much more if you want to get into high quality HD video.
Steve