XpressAlarm - application for Nokia 5800 and N97, which helps to protect your phone against theft.
Enough to include a program to lock the phone, put it in his pocket, and wait for the sound the alarm.
If your phone out of his pocket, delivers the siren!
To ensure that the siren is not sounded, just unlock your phone.

In the settings you can set the time to lock and the time before the sounding of the alarm, as well as to disable all sounds, except for sirens.
The program, established need python (download), not lower than version 1.9.4.
Do not forget also the point about support for the menu:)
Download Xpress Alarm