Startup can be more fun if you know this:

Press X during startup Force Mac OS X startup

Press Option-Command-Shift-Delete during startup Bypass primary startup volume and seek a different startup volume (such as a CD or external disk)

Press C during startup Start up from a CD that has a system folder

Press N during startup Attempt to start up from a compatible network server (NetBoot)

Press R during startup Force PowerBook screen reset

Press T during startup Start up in FireWire Target Disk mode

Press Shift during startup start up in Safe Boot mode and temporarily disable login items and non-essential kernel extension files (Mac OS X 10.2 and later)

Press Command-V during startup Start up in Verbose mode.

Press Command-S during startup Start up in Single-User mode (command line)