A user notification system and a computer input device, such as a mouse. The computer input device includes an illumination member that enables a user to quickly and accurately position the input device during poor lighting conditions and determine whether the computer is ON. The input device includes a housing and an illumination device that is supported by the housing. Illumination from the illumination device is visible when the input device is placed on a support surface. The illumination member is also used to notify the user if one or more of various events have occurred in a computer application being run on the computer. The notification information is presented to the user by changing the state of the illumination member. An example of event for notification includes the receipt of a message in a communications program such as an e-mail message. The notification can make the illumination member blink as a function of the number of messages received. This enables information to be conveyed to the user without the need for text or audio, and without the need to view the computer monitor.