If you have a microphone, you can use internet telephony software
such as Google Talk to talk with your ICC friends. You can download
Google Talk from talk.google.com. Other popular free chat packages
include NetMeeting and Skype.
Channel 204 has been designated for discussion of telephony
software, and for ICC members to work out how best to call
one another.
There may be some security risks to using some of this software.
Anybody you talk with can probably get your IP number, but that's
normally no big deal. Beware of things like NetMeeting's sharing
features.