Tired of “bloop” and “boit”? You can assign any sound file to actions in iChat, such as when a buddy logs in or someone invites you to chat. Pixelhaus has made a collection of Matrix-themed sounds available today, which are pretty good. The other sets for Wild West and LV426 (Alien) are also done well.
Simply copy the sound files to
~/Library/Sounds and restart iChat. Then go to iChat’s preferences, click the Alerts icon, and reassign sound files for each action.