This wiki page documents other ways to install CHDK on your camera's SD card. It extends the functionality of the camera without changing (flashing) the camera's firmware.
Two methods are available to load CHDK into camera memory: the Firmware Update Method and the Bootable SD Card Method.
These utilities can partition and format bootable SD cards and download & install CHDK to those cards.
To use this method, format and load the card using the instructions below, and then set the card's lock switch (the little slider mechanism on the side of the SD card) to the "LOCK" position.
Insert the card into your camera and turn it on normally - you should briefly see the CHDK logo, indicating that CHDK has successfully loaded.
For recent cameras, a single FAT32 partition configured to be bootable is the preferred SD card configuration for automatically loading CHDK. This format cannot be used for autobooting - you must reformat these cards as FAT32 on your PC.
Note also that newer cameras do not support dual partition CHDK booting.