QPEApplication::grabKeyboard()
QPEApplication::ungrabKeyboard()

After you grab the keyboard you can not open a child widget for the applicaiton might now ungrab the keyboard on exit.
Calling grab, then ungrab at the end of the app has been reported with semi success.
keyEvent()

Activity Qt::Key_F9
Contacts Qt::Key_F10
Home Qt::Key_F11
Menu Qt::Key_F12
Mail Qt::Key_F13
Select Qt::Key_Space
The directional keys are all rotated 270 degrees.
Left Qt::Key_Up
Up Qt::Key_Right
Down Qt::Key_Left
Right Qt::Key_Down
Cancel Qt::Key_Escape

For a complete listing of all of the keys see the 2 following documents keycode's for Qt and keycode's for Java