Off the top of my head:
Alt/Option ------------boot select
Shift ----------------- safe boot
CMD+S -------------- single user mode
CMD+V -------------- verbose mode
CMD+option+P+R -- reset PRAM
CMD+R--------------- recovery
C --------------------- boot to cd
N --------------------- boot to network
D --------------------- boot to AHT
T --------------------- target disk mode
Eject key ------------ eject disk before boot