Collection Procedure (kernel panic)
http://docs.info.apple.com/article.html?artnum=106228
looking for panic.log/Library/Logs

Kernel Panic FAQ
http://www.index-site.com/kernelpanic.html

CrashLogger (application failure)
http://developer.apple.com/technotes/tn2004/tn2123.html
user’s home directory~/Library/Logs/CrashReporter/.crash.log)/var/log/system.log

Hardware Test (PowerPC)
http://docs.info.apple.com/article.html?artnum=86287

Hardware Test (Intel)
http://docs.info.apple.com/article.html?artnum=303081

Example to identify kernel panic:
http://www.index-site.com/kernelpanic.html