Props to Vitali Virulaine at http://www.vital.pri.ee/PSTN/ for coming up with, and sam for inspiring me to show him up, I hope you get into the maxim party!!!
Step 1: Parts needed
-an RJ11 Plug (buy a cheap phone cord and cut off one end)
-2 100OHM resistors
-500OHM variable resistor
-2 3.3uF capacitors
-9V adapter, or USB plug, or use the one currently in your phone.