I have an Intel MacBook Pro.
In my office I have a 30" Cinema Display, wireless keyboard and USB mouse (attached to the display). I have a spare power block next to the display.
In theory I should just arrive, switch on the keyboard, plug everything in to the MacBook(video, usb and firewire connections from the display, power and ethernet from the wall), and go!
In practice, sometimes it worked, and sometimes the MacBook would refuse to talk to the display. Worse still, it would refuse to wake up if I disconnected everything, and tried to run stand-alone. Until I found the secret, I had to force a reboot with the power key.
The secret is, connect the power first!
Connect the power, plug in video, usb, firewire, ethernet. The computer wakes and the display comes to life. Turn on the keyboard, type a few characters (type them somewhere non-critical). A couple of characters may get lost initially, but once the connection is established, everything is fine.