From what I understand, there are only a handful of cameras that can be controlled by a computer. The software I am using is called VM95. It is free, and can be found here: http://www.video-monitoring.com/hobbyist.htm
I have only been using it for about a week, but I am really happy with it. It has had no problems, and the weather station is only a 800 MHz Pentium III, running WD, VM95, and the Salsas.