This is the Maple Phone concept designed by Hyun Jin Yoon and Eun Hak Lee, who have won the Silver award at the International Design Excellence Awards 2008. The Maple phone is a slider phone with touch sensitive keys that have backlight. As you slide the phone, you can see the phone’s LCD display. The phone will also have integrated camera and music player.
It would probably use the capacitive touch technology, which is a special panel coated with indium tin oxide or a similar material capable to conduct continuous electrical current across the sensor.
More pictures after the break: