To check your Mobile phone's serial number, key in the following digits on
your phone: *#06#
A 14 - 17 digit code will appear on the screen. This number is unique to
your handset. Write it down and keep it somewhere safe. Should your phone
get stolen, you can phone your service provider and give them this code.
Provided that the service is available in the country where the mobile
was stolen, they will then be able to block your handset so even if the
thief changes the SIM card, your phone will be totally useless. You
probably won't get your phone back, but at least you know that whoever
stole it cannot use/sell it either.
P.S. This is true for all handsets regardless of make.