The Canon EOS 300D (marketed as the Canon EOS Digital Rebel in the USA) was one the first sub-$1000 digital SLRs.
There are several firmwares available, that extend functionality and add stability:
Undutchables 0.2.3—considered best (MD5: e179d4b155c5f12ed8ffc11d5b8c418f)
Canon's original v1.1.1 firmware—for reference (MD5: 327354c4697db3d936cc724258e7517f)
Canon has detailed instructions for flashing firmwares on the EOS300D. The instructions, in short:
Format a CompactFlash memory card.
- Copy the firmware file (*.fir) to the root of the memory card.
- Insert the memory card into the camera, and turn it on. The camera should prompt to install the firmware upgrade.
- Format the memory card again before attempting use.