How to find a cause of a Kernel Panic message, or BSoD?
The kernel panic text is added to the log after you restart the computer, assuming that you did not reset PRAM (the kernel panic text is stored in PRAM until you restart). In Mac OS X v10.6, the logs are located in in /Library/Logs/DiagnosticReports. In Mac OS X v10.5, the logs are located in /Library/Logs/PanicReporter (source)


If you cannot find these files, or they contain no information on the kernel panic, then there is likely something wrong with the hardware of the computer.  Running a system diagnostic or visiting the genius bar is probably your next step.

If you are really interested in attempting to resolve the issue yourself, you might find this guide to resolving OS X kernel panics helpful.