Patent ID: 7359943

Claim:
A method for enabling a guest user who is not a registered user of an instant messaging system to communicate by instant messaging with a registered user of the instant messaging system, the method comprising: receiving an initial indication that the guest user desires to communicate with a selected registered user of the instant messaging system by instant messaging, wherein the initial indication specifically identifies the selected registered user with whom the guest user desires to communicate; wherein the instant messaging system is associated with at least one other registration-based service; wherein the guest user is registered with the at least one other registration-based instant messaging system and wherein the guest user signs in using a user name to access the at least one other registration-based instant messaging system; displaying the user name associated with the guest user with respect to the other service to identify the guest user to the selected registered user; sending to a client computer system associated with the guest user browser-executable computer code comprising computer instructions for providing at least limited instant messaging functionality to the guest user at the client computer system, without requiring the guest user to download and install client side instant messaging application software and without requiring the guest user to register as a user of the instant messaging system; wherein providing at least limited instant messaging functionality to the guest user includes displaying to the guest user an interface that includes controls for sending instant messages to the selected registered user, but does not include controls for one or more features provided by the client side instant messaging application software; and facilitating an instant messaging session between the guest user and the selected registered user.