Citizen Engineer is an online video series about open source hardware, electronics, art and hacking by Limor (Ladyada) Fried of Adafruit Industries & Phillip (pt) Torrone of MAKE magazine. The first video debuted at "The Last HOPE" conference in New York City.
Volume 01 - Phones: SIM card & payphone hacking
Learn how a SIM card works (the small card inside GSM cell phones), make a SIM card reader, view deleted messages, phone book entries and clone/crack a SIM card.
Modify a retired payphone so it can be used as a home telephone and for VoIP (Skype). Then learn how to modify the hacked payphone so it accepts quarters - and lastly, use a Redbox to make "free" phone calls from the modified coin-accepting payphone.