I put CHDK on my wife's camera, and it does a lot of stuff. Fast shutter speeds with flash sync, intervalometer, raw capture, HDR, motion detection, etc. I have tested most of this stuff and it works. I notice as I work with CHDK more, I get better at it. It used to seem like it did random stuff, but now I realize there are lots of little tricks to using it that are not documented. I don't know about the SX230, though. I'm a little nervous, especially since I didn't confirm the firmware version before ordering the camera. Maybe I'll need to get another camera dedicated to CHDK. Wish me luck.