Anti-theft device/ELT-lite etc?

Posted elsewhere, having seen a thread on stolen avionics, I just saw
an advert on TV for a device that could be useful to detect impending
theft, and/or act as a sort of locator beacon, etc. (designed for
tracking kids, pets, whatever and texting to your mobile phone when it
moves where it shouldn't).

Has any one used one of these? Do they do what it says on the tin?

"Personal GPS Tracker
product code: MAX415
Price: £149.00


Keep track of your property or your loved ones...
It's the most versatile tracker around. MAX TV's Personal GPS Tracker
is a tiny device, around the size of a matchbox. When fitted with a
standard mobile phone sim card (we recommend Pay as You Go), you can
call the tracker to get its location co-ordinates texted back to you.
Type them into Google Earth, and you have its precise map location!

.. . .. If you're worried about your child, . . . getting lost, just
give them the tracker and you can find out where they are with one
quick phone call. You can protect your car, caravan, boat or motorbike
from theft - just hide the tracker in the vehicle, and if it's
pinched, tap its co-ordinates into Google Earth to find out where it's
been taken.

.. . . a number of useful settings. Auto Track reports the tracker's
GPS position via text message every 30 seconds, whereas Fence Mode
alerts you if the tracker moves out of a designated area . . . .
Movement Alert activates the tracker as soon as it's moved, and Speed
Alert is triggered when it's transported at or over a set speed.

With Real-Time Monitoring activated, the tracker texts real-time GPS
information to your mobile, and its SOS Button instantly sends its
position co-ordinates to all stored numbers.

.. . in-built microphone makes it a great bugging device. Just leave it
in place, phone the tracker and you can listen in on what's going on
around it (make sure you comply with the law)."

Chris N.