Essentially what I want to do is when either A) the camera detects motion or B) some sort of notification is given the camera starts recording a video, preferably but a few pictures would suffice but wouldn't have the effect I want. It will be very similar to a security system hooked to a door. Whenever somebody opens the door they are caught on camera. I'm fairly new to CHDK, just started a day ago and actually bought my camera specifically for this and this usage so I'm not sure if this script will be very complex or not but any help would be greatly appreciated. Thanks!
A small script is all that is needed.
Detecting motion takes one line (once you get the parameters tuned the way you like).
Starting video is another line - plus a few lines to stop video after a specified delay.
What is impossible to tell from your description is what you mean by "some sort of notification is given". You could probably rig up a USB remote setup that would tell you when the door had opened in your example if that's what you want.
BTW - what camera did you buy and have you suceeded in loading CHDK onto it ?