Many publications say about use multi SIM in mobile phones. Very popular Silver cards SIM (and other). SIM holder and SIM is one of lagest element in GSM/GPS trackers. Roundsolutions use ST chip to implement SIM on chip on new mini tracker project. As i know from publications multi SIM cards build on PIC16F876 with 8/32KB EEPROM. I decide implement SIMonChip technology on AVR ATmega168 microprocessor. On of big problem in this project - how to know IMSI and Ki codes. But if you a legal mobile customer you can write request to mobile operator and know this codes (or crack it as describe on kiscan.net - be carefull with program from this site).

First i decide emulate PIC16F876/24C256 (Silver card - SimEmu 6.02) and ATMega644P (small arduino pde) with Proteus.
SmartScan (from kiscan) see this emulation project as SIM card (empty or configured).
Now port PIC program to ATmega assembler and realize in hard.