1. A system for communicating with a computer comprising: a) a capture device wearable by a user, the capture device having sensors to monitor the user's mental activity and to capture a particular brain activity pattern indicative of the mental activity generated in the user by a particular subject; b) at least one data storage device operable for storing a plurality of stored brain activity patterns, each of the stored brain activity patterns being associated with at least one computer readable indicia indicative of a subject that generated that brain activity pattern; and c) at least one processor operatively connected to the capture device and the at least one data storage device, the at least one processor being operable to: (i) receive the captured brain activity pattern, (ii) compare the captured brain activity pattern to each of the plurality of stored brain activity patterns in the data storage device to determine if the captured brain activity pattern matches at least one of the stored brain activity patterns, and (iii) if there is at least one matching stored brain activity pattern, retrieve the at least one indicia associated with the at least one matching stored brain activity pattern.