Electronic compass - Connecting it to a PC?

I'm developing a software and the software has to know where the hardware is oriented to (North, West, etc...)

I want to buy in ebay a circuit like this (or similar):
**broken link removed**

My question is what are the steps to introduce the information from the circuit to the computer. I want to use a RS-232 connection or USB.

Maybe Arduino would be the best option? Maybe other?
I want also to use 4 circuits at the same time, that are connected to the computer.

Your compass talks I^2C or IIC. Not something that a PC normally talks. I have a adapter that plugs into the parallel port and through software talks IIC. Many PCs now do not have a parallel port. And the software is for Win95.

It would be easy to add a very small micro computer and RS-232 translator. Or make a USB-micro that plugs into the compass and talks USB to the PC.

Already done....... https://arduino.cc/playground/Learning/Hmc6352 Go for it...

Ian, good find. I went to sparkfun.com looking for a USB to IIC converter but did not find one.