How to connect cellphone to PIC

I want to have GPRS communication on my uC. I figure out that its cheaper to get some old phone and connect it to PIC and send AT commands etc etc. But i didnt find any example how to connect it (hardware). How to know where from where to get wires from phones UART? Can it be done from any phone that can go to GPRS or is there some restrictions? I still dont know what phone will i use

I have limitted knowledge in this area, but the only cell phones I know with an interface connection are the newer intelligent phones with USB connectors.

I've had cell phones since they first had small LCD screens and slide-out antennas, before StarTrek flipflops, after the humungous first models that weighed 5 pounds. The only jacks I remember were either for charging or earplugs.

The newer phones also offer bluetooth and wifi connectivity.

Robert


EDIT: Check this:
http://www.dudek.org/blog/257