Johnson777717,
Thanks for trying and having a look for me. Your effort is appreciated.
I have been having a look around the net and on component web sites. I have discovered a SMD IC called a KMZ51. It is produced by Phillips and it is called a Magnetic Field Sensor. I have only managed to find one data sheet for it, and it wasn't very informative!
Does anyone know anything about this device? could it be what I am looking for? Failing that, how feasable is the idea of having a ring of opto sensors and some sort of weighted spndle, like a normal compass. Or a series of coils, measuring the flux through them or something!?
Any more help from anyone, would be very much appreciated
Thanks.