On most cameras, using some combination of prefix and extension for raw allows you to transfer these files over USB, assuming you restart the camera before plugging it in.
Any idea what that combination would be for an SX20is?
The "raw in directory with jpeg" option may affect this as well.
What do you mean... leaving that option ticked would allow me to transfer raw files along with the jpgs via usb cable? Or the other way around?
Note some software that copies pictures over USB for you may also have problems with raw files or be confused by your choice of prefix/extension. Browsing the camera in explorer is less likely to have this problem.
I see that. It's just kind of anoying (annoying?).
If this doesn't work with your camera, then a card reader or the CHDK PTP stuff are the only other alternatives.
I'll check that. See if it suits me.
If you find the whole partition swapping thing to be too much of a hassle, it might be worth obtaining one or more 4gb cards just for CHDK formatting them fat16.
Or you may decide that CHDK raws don't really add enough benefits to justify the extra effort most cases, and stick to jpeg 
That's what I was thinking since the only reason for doing this whole swapping thing is to manually copy raw files to the hard drive. I've been watching these raws and I begin to understand the potential in them once in a photo edition soft. But, as you say, maybe for the general use, ocasional shooting, JPGs might be more practical. Specially if I set superfine quality, right?
Well, thank you all for your help. It is evident that I had not installed chdk properly.
I'll continue my exploring and learning all these new functions (I can't believe something like this exists!)
Thanks
