The Hal itself program can handle many simultaneuous conversations. Unfortunetely AOL puts a limit on how many IMs you can send out and you'll definetely hit AOL's limit before you hit Hal's limit. I'm not sure what the exact limit is as it varies based on your current warning level and your warning level over the history of your account. AOL does this to prevent spam bots from sending IM's to thousands of people at once, but it also prevents legitamate bots like Hal from carrying on many simultaneous conversations.