Just wanted to pass along that I became interested in time lapse photography and this wiki really helped get me going. I own a SX230HS and am very pleased with it, it keeps surprising me with features and high quality shots for such an inexpensive camera.
If you are interested in installing CHDK on this camera I would highly recommend taking a look at my site http://www.intervalometer.org because I have found the holy grail of installing CHDK on any camera, trust me, it's basically a one click install and worked for me the first time.
All the steps on this site can be a little confusing and daunting to sift through. Just trying to make your life a little easier because this tool that I found allowed me to be up and running with CHDK on my camera in about 15 minutes flat.
Once you go time lapse you never go back!
My Intervalometer website