The SIM Doctor is indeedy a rather cool bit of gear (although it apparently won’t work with some of the more advanced encrypted SIM cards). € 69.00.
‘SIM DOCTOR USB with 10in1 Card…can combine 10 most frequently used mobile numbers (SIMCards) from different areas, countries or different networks numbers in just one SIM card. A smart design of this MultiSIM can now solve problems for people who own several mobile numbers and always wonder which one to bring when they go out. With this MultiSIM card, you can combine all your mobile numbers in this MultiSIM card.’