This article was published by the Guardian (UK) today about how a journalist tracked his girlfriend using her cell phone.

For the past week I've been tracking my girlfriend through her mobile phone. I can see exactly where she is, at any time of day or night, within 150 yards, as long as her phone is on. It has been very interesting to find out about her day. Now I'm going to tell you how I did it...

I unplugged her phone and took it upstairs to register it on a website I had been told about. It looks as if the service is mainly for tracking stock and staff movements: the Guardian, rather sensibly, doesn't want me to tell you any more than that. I ticked the website's terms and conditions without reading them, put in my debit card details, and bought 25 GSM Credits for £5 plus vat.

Almost immediately, my girlfriend's phone vibrated with a new text message. "Ben Goldacre has requested to add you to their Buddy List! To accept, simply reply to this message with 'LOCATE'". I sent the requested reply. The phone vibrated again. A second text arrived: "WARNING: [this service] allows other people to know where you are. For your own safety make sure that you know who is locating you." I deleted both these text messages...

Now, the article neglects to go into much detail about which service the reporter used, and naturally, I was curious, so I did a little digging myself.

There are a few companies in the UK that provide a GSM cell phone tracking service. As far as I can tell, Accutracking and TrackMyKids.Com are the only companies in the US that provides a similar service. However, they both require your victim target mark girlfriend/boyfriend/love-interest to carry a Nextel Motorola phone. If they use another service, you may have to resort to more traditional, or more high-tech stalking methods.

If all else fails, just make them a mix CD of songs that mean something to you about them. That always works.