I have only tested this on iPod Touch jailbroken iOS4, but I don't see why it wouldn't work on iPad or Iphone. Here's what you'll need: -> Jailbroken iPod Touch/iPhone/iPad -> Erica Utilities package from Cydia -> Netatalk or OpenSSh -> The chime file: http://leechjr.ath.cx/public/AppSnd/chime.caf.zip -> The PLIST file: http://leechjr.ath.cx/public/AppSnd/plist.zip (Copy and paste the link into your address bar) What to do: From Cydia, install Erica Utilities. This is what allows the file to be played through command-line. Access your iDevice system file using one of the to ways suggested above. Upload the sound file in the "/System/Library/Audio/UISounds" directory of your iDevice. Important the file name must be "chime.caf". Upload the plist file in the "/System/Library/LaunchDaemons" directory of your iDevice. Reboot your iDevice. You should now hear the chime somewhere in the boot process. This has been tested with a Jailbroken iPod Touch 2G with firmware 4.0 If there's a broken link, just say it in the comments, and I'll fix the issue.