1. A system for performing diabetes self-care using at least two devices in communication with one another, comprising: (a) a blood glucose monitoring device associated with a user, including (i) a receptacle for receiving an amount of blood sufficient for the blood glucose monitoring device to run a blood glucose test sequence, (ii) processing circuitry for controlling said blood glucose test sequence and computing a blood glucose level, and (iii) a power source for powering the blood glucose monitoring device; and (b) a portable microprocessor-based device associated with said user, separate from the blood glucose monitoring device and configured for receiving blood glucose test results directly from said blood glucose monitoring device, said portable microprocessor-based device including (i) a microprocessor that executes program instructions stored in a memory, said program instructions when executed performing analysis of the blood glucose test results and detecting a need for a change in insulin dosage, and (ii) said memory for (A) recording the blood glucose test results received from the blood glucose monitoring device, (B) storing said program instructions for establishing a data protocol that allows digital data signal processing, (C) storing said program instructions for performing said analysis of the blood glucose test results, (D) storing time and date tags associated with the blood glucose test results and (E) storing calibration information.