Mac OS X: ~/Library/Logs/CrashReporter/MobileDevice/<DEVICE_NAME>
Windows XP: C:\Documents and Settings\<USERNAME>\Application Data\Apple Computer\Logs\CrashReporter\MobileDevice\<DEVICE_NAME>
Windows Vista: C:\Users\<USERNAME>\AppData\Roaming\Apple Computer\Logs\CrashReporter\MobileDevice\<DEVICE_NAME>
Windows 7: C:\Users\<USERNAME>\AppData\Roaming\Apple Computer\Logs\CrashReporter\MobileDevice\<DEVICE_NAME>