I had been to “The MobileStore” at Annanagar, 2nd avenue, chennai last evening, and was in the search for Scratch guard for my Nokia N70 as soon my eyes was on the samsung SGH- E250 with a special feature saying Mobile tracker, It got my attention. This mobile has all features of Nokia N70 + wifi + Mobile tracker - theft guard and the best price is 7800 INR (approx) i.e half the price of Nokia N70.
I personally feel having two credit card sized devices one on the mobile and another one on you neck or your hand or in your wallet is another pain in the butt.
If you could forget your mobile, you could also forget taking the card sized device.
I would say the best option would be a mobile which automatically would sends sms to your pre configured mobile numbers as soon one changes the SIM card.
Kindly Note: Most models of Samsung Mobile phone has the Mobile tracker installed by default.
Convergence: when the whole world is looking forward to have all controls under one device, for instance mobile phones have integrated Music, Photos and Internet access. Why do we want the Mobile tracker be another piece of hardware on your butt. Just consider the user experience of carrying two device at a time