A handheld computing device comprises a thin enclosure having two opposing major faces. A display screen is disposed on a first one of the major opposing faces of the enclosure and a touch-sensitive object position detector input device is disposed on a second one of the major opposing faces of the enclosure....http://www.google.de/patents/US5543588?utm_source=gb-gplus-sharePatent US5543588 - Touch pad driven handheld computing device
