I have collated a lot of this myself from different manuals and as far as I know they are correct. If they aren't post a reply and I'll update them.

Acer Extensa 2000/2500 Series --- Far right launch button above the keyboard
Acer Travelmate C Series ---Far left hot key and then choose WLAN from menu that appears
Acer Aspire 1000 Series --Launch Keys above the keyboard
Acer Aspire 1640Z ---- Launch Keys above the keyboard
Acer Aspire 1690 ---- Launch Keys above the keyboard
Acer Aspire 2000 Series ---- Button on the front of the laptop
Acer Aspire 2012 ---- Launch Keys above the keyboard
Acer Ferrari 3000 ---- Button on the front of the laptop
Acer Ferrari 3020 ---- Button on the front of the laptop
Acer Ferrari 3400 ---- Button on the front of the laptop
Acer Ferrari 4000 ---- Button on the front of the laptop
Advent 7086 ---- Button next to the power button
Advent 7096 ---- Button next to the power button
Advent 7100 ---- Fn / F2
Advent 7104 ---- Fn / F2
Advent 7201 ---- wireless key top right and then Fn / F2
Advent 8117 ---- small slide switch on the front of laptop
Asus ---- Fn / F2 (some models may have a switch)
BenQ Joybook 5000u-d09 ---- Fn / F12
Compaq Armada Services ---- Not Wireless
Compact presario ---- Button on the back
Compact presario M2000 ---- Button above the keyboard (antenna icon on button)
Dell Inspiron series ---- Fn / F2
Dell Inspiron 500M ---- Fn / F2
Dell Inspiron 600M ---- Fn / F2
Dell Inspiron 1510 ---- Fn / F2
Dell Inspiron 5100 ---- NOT WIRELESS
Dell Inspiron 6000 ---- Fn / F2
Dell Inspiron 8600 ---- Fn / F2
Dell Inspiron 9300 ---- Fn / F2
Dell Latitude D400 ---- Fn / F2
Dell Latitude D500 ---- Fn / F2
Dell Latitude D600 ---- Fn / F2
Dell Latitude D610 ---- Fn / F2
Dell Latitude D620 ---- Fn / F2
Dell Latitude D800 ---- Fn / F2
Dell Latitude X300 ---- Fn / F2
Dell Vostro 1500 ---- big button on left side at rear no FN combo to activate
e-machines M series ---- Fn / F2
E-System 3115 ---- Slide switch on front of laptop Also has Fn / F5 function
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
Gateway Laptop ---- Switch on side and then Fn / F2
HP nc4000 ---- Button above keyboard
HP nc4010 ---- Button above keyboard
HP nc4220 ---- Button on left next to USB port
HP nc6000 ---- Button above keyboard
HP nc6220 ---- Button above keyboard
HP nx9010 ---- Button on front
HP omnibook 6200 ---- Button on the left
IBM T43 ---- Fn / F5
IBM X32 ---- Fn / F5
Lenevo ---- button on the front
Medion ---- Fn / F1
Packard Bell EasyNote E2 ---- Fn / F1
packard bell: easy-note MV46/008 ---- Fn / F1 to turn on/off
packard bell MZ36-U024 ---- Fn / F2 to activate
Sharp Laptops ---- Fn / F2 to activate
Sony Viao ----- Button on the front or right hand side or slide switch
Sony VAIO VGN-AX570G ---- Front left button
Targa Companion 811 ---- Fn / F2
Toshiba Eqium Series ---- Slide switch on front of laptop
Toshiba LibrettoSeries ---- Slide switch on Left hand side
Toshiba M1 ---- Switch on left towards front
Toshiba M2 ---- Switch on left towards front
Toshiba Portege Series ---- Slide switch on the left hand side
Toshiba Qosmio Series ---- Slide switch on the left hand side
Toshiba Quantium Series ---- Slide switch on the left hand side
Toshiba R100 ---- Switch on right hand side
Toshiba Satego Series ----- Slide Switch on the right hand side
Toshiba Satelitte ---- On the Front under lip then Fn / F8
Toshiba Satellite Pro ---- On the Side or front
Toshiba Tecra 2100 ---- Switch on left
Toshiba TE2000 ---- Switch on left