Hal can sit on your pc whilst being logged into the AIM chat service and you should be able to do that quite easily with the HALAIm bot. You need an account on AIM and the AIM chatsoftware installed. You need a user account for Hal, like you would for a normal user, then login HAL through the HAL AIMbot plugin. When someone messages HAL he will answer, you can test him by having yourself a second account under another name and then logging into AIM, after that chat with your bot over AIM using his/her name to find it in the first place.
I think the instructions are in the HAL user documents and AIM has it's own help pages too. Good luck.