For any reference point on the Earth, the qibla is the direction to the Kaaba. Muslims are ordered to face this direction during prayer (Qur'an 2:143-144). While it may appear to some non-Muslims that Muslims worship the Kaaba, it is simply the focal point for prayer.
According to Islamic tradition, when Muhammad was praying in the Qiblatain Mosque (in Medina), he was ordered by God to change the qibla from Jerusalem to Mecca and the Kaaba. Various theories are advanced as to the reason for the change.
Qibla compasses are available that tell Muslims which direction to face no matter where they are. This method requires one to align the north arrow with a particular point on the compass corresponding to one's location. Once so aligned, one simply turns toward the direction indicated by the compass's qibla pointer, which is often in the shape of a minaret. "Qibla numbers" for various locations are listed in an accompanying booklet and also indexed online.
Ref : http://www.stanleylondon.com/qiblanumbers.htm
