Have you ever suffered a problem where your Mac would not start up properly? What key combination can you use to eject a DVD at startup? How do you start up in safe mode? iStartup will tell you which key combinations to use.
iStartup can be particularly handy if your Mac refuses to start up. Without a healthy Mac, obtaining a list of key combos suddenly becomes much more difficult. And while MobileSafari is great, it is not always an ideal solution for quickly looking up information.