Hi fellow BlackHat dudes!

I might post this in the wrong forum but I thought maybe one of you clever guys knew this... :

I know it is possibile to trace/track a GSM mobile telephones location all over the world.
I also know some compaines does this for £150 (3 searches), but I am pretty sure it is possibile to do it for free as well!

I am VERY interested in getting this for free! (I bet you are also)

Anyone know how to do this without emty our pockets??

Thanks,
Gathom