Provided you use Google Talk (I don't think they support AIM), then I am convinced that setting it up through Instant Message is the best way. It saves you having to have a whole new application there. Plus, that way it is there wherever you log on (wherever you may be) I think the SMS option is cool and use it, but most people don't use it I think, so I won't really bother recommending it to you that much other than this mention.