Ergonomic computer mouse

A computer mouse comprising a main body defining a generally upwardly facing surface portion on which a user's hand is positionable and a downwardly facing generally flat surface part for positioning on a work surface, and a button member mounted on said main body and defining an outwardly facing surface portion selectively actuable by a user to transmit a signal to a computer in communication with said mouse, at least one of said main body and said button member including a projection extending outwardly from said surface portion thereof for physical contact with the hand of the user, a base of said projection occupying a minor part of the surface area of said one surface portion.