...
http://www.acquisitionx.com/
. Something to do with file-sharing (Limewire network), whatever that is. Never use it myself.
IRC chat clients for mac:
AOL and iMac. Both work with Apple's iSight video chat system!
For Tiger OS :
Quicksilver
http://mac.softpedia.com/get/Utilities/Quicksilver.shtml
Quicksilver allows you to navigate to what you need quickly and easily, while keeping your hands on the keyboard. For example, if you want to launch an application hidden in the depths of your file system, simply activate Quicksilver with a keystroke, type a few letters of the application's name, then hit Return or Enter to launch it. When you don't need Quicksilver, it keeps out of your way, preserving screen real estate. (Doug, Diane and Debbie are using)