You probably know that the 5800 XPressMusic has an accelerometer that automatically changes the screen from the Portrait to the Landscape mode when you rotate the mobile device. But there are two other useful settings on the 5800 XPressMusic. You can flip the mobile face down and instantly silence an incoming call or snooze and alarm.
The Sensor settings on the Nokia 5800XPressMusic can be found here. By default, Sensors are enabled on the mobile.
Menu –> Setting –> Phone –> Sensor Settings –> Turning Control
In the first accelerometer supported device, the Nokia N95, third party developers created an application called FlipSilent (because Nokia didn’t support it in the earlier devices).