Mark Bridge writes:

A few weeks ago I received a phone call out of the blue. It went something like this:
“I think my partner's cheating on me. How can I get into the GPS on his phone to find out where he is?”

I'm no secret agent. I wasn't comfortable giving too much information and ended up suggesting that a private detective would probably deliver evidence that was more conclusive. Nevertheless, it got me thinking.

Of course, you could enable Google Latitude on the other person's phone – or set up geo-location on their Twitter account – but all this is a bit hit and miss. What if they don't use it?

One solution is to install software on their phone. If you're able to do this – and they're using a smartphone – there are plenty of mobile phone spying techniques available. For example, Android users could be living in fear of SMS Secret Replicator from DLP Mobile. It secretly forwards incoming text messages to another phone. The program itself is hidden once it's installed, although an itemised bill will make the text trickery pretty obvious.

If you're after someone who uses an iPhone, similar software can let you browse through the phone's photos and automatically upload GPS positions every half hour. You'll need the iPhone to be jailbroken, so once again it's not all plain sailing.

And don't worry; Symbian users haven't been left out!

But why not get hold of your own mobile phone technology to find out what's going on?

You can now bug someone from miles away – even from another country – thanks to a mobile phone call. A bedside alarm clock can have a 3G video camera built in. Even an innocent mains adaptor could listen to someone's conversations.

Let's face it, a mobile phone set to 'silent' and 'auto answer' in a desk drawer may well be all the spy equipment you need.

And if not, the James Bond style of GPS tracking bug is now available for little over £100.

Just remember a couple of things. Firstly, if you're spying on someone, the moral high-ground may be a long way above you. And secondly, make sure you stay on the right side of the law. Otherwise your next phone call may be the last one you make for a long while!