from bitter bitter experience not all fu lappys have a physical switch ......
some use a dedicated key/combinaton
http://forums.speedguide.net/showthread.php?t= 214308
says
Fujitsu Siemens Amilo A Series ---- Button above the keyboard on top right
Fujitsu Siemens Amilo D Series ---- Button above the keyboard on top right
Fujitsu Siemens Amilo K Series ---- Not Wireless
Fujitsu Siemens Amilo L/EL Series ---- Fn / F1 to turn on/off
Fujitsu Siemens Amilo La Series ---- Fn / F2 to turn on / off
Fujitsu Siemens Amilo Li Series ---- Easy launch button (one of 3) on top of keyboard
if yours isn't listed it should be something similar