In the past I have found two companies that offered one sim card with multiple (international) numbers attached to it. The first one, of which I forgot the name, offered one sim card with the possibility to add different european numbers to it. They don't longer exist, hopefully because they were ahead of their time.
I recently learned of the existence of a Surinamese company that offers a so called "two country sim". It gives both a Surinamese and a Dutch mobile telephone number. You are always available through both numbers. Both in the Netherlands and in Suriname you won't have roaming costs. The company aims at the large Surinamese community in the Netherlands.
I do like this concept. Since I travel frequently I would really like to have such a sim card. Since telesur proves that the technology works, there should be others. Does anyone know of similar companies, preferably combining Belgian, Dutch, German, French and UK numbers?