Of course, you don’t want to be typing in your location into a web site every time you move, so there are a lot of applications that figure out your location and tell Fire Eagle. There are many of them, and the one that I have used on my Nokia E71 is the Fire Eagle mobile updater for J2ME. Every minute, it checks my phone’s GPS and sends its location to Fire Eagle.

With my old Palm Treo 750V, I used Mologogo, which tried to guess my location based on cell tower information. Its accuracy isn’t that great (usually to within a kilometre) but it’s good enough to play around with.

More mobile updaters are available here.

So Fire Eagle knows where I am. What use is this?

Well, I built a Google Maps-based tracking system. You authorise Fire Eagle accounts with the application, and then every minute or so the map will update showing the location of those people.

It’s not a very effective spy tool, because you’ll either need to spend a few hundred dollars on a GPS-enabled device and plant it on your target, or gain access to the target’s phone, put a Fire Eagle updater on it and then authenticate that user with the application. But it’s still possible. And cool.

I wrote it the backend (which is pretty simple) in .NET because that’s what I’m good at, but seeing that this server isn’t Windows, I have rewritten it in PHP, and added simple site registration so that anyone can use it and become a spy. (I wrote that paragraph before I had actually done the PHP version – took about 4 hours in the end.)

So, go to http://arunstephens.com/spy/ to become a spy!

If any government agencies find this useful, please let me know!