Most of the hotkeys of my Thinkpad wok fine with KDE 4.2 (Fn+F4 Suspend to RAM, Fn+F12 Suspend to disk, Fn+F5 act/deact bluetooth, volumes, start/stop/previous/next). Fn+F7 (select Display) and Fn+F8 (act/deact Touchpad) don't work yet.
To act/deact the touchpad I found the following comand :
/usr/bin/synclient "TouchpadOff=`/usr/bin/synclient -l | sed -ne 's/\(TouchpadOff *= *\)\(\)/\2/p' | sed -e 'y/01/10/'`"
Now I'm searching a way to map the key in KDE4 without installing hotkeys or other programms.