Today we can rather often meet people having two cell phones or using a special adapter for two SIM-cards. The statistics shows that number of such people in USA is about 16% out of all having cell phones. Usually one of the phones is for work and the other for private needs. The main reasons are: some companies offer special corporate tariff plans to spare money and using such numbers with private purposes is forbidden. Among other reasons: better tariffs or coverage by other carrier, unwillingness to change the number, efforts not to mix busi\ness and private life – in the last case one can just turn off the “business” phone in non-business time