Colloquy for iPhone and iPod touch gives you the 20 year old IRC protocol in your Apple mobile device. It is another in a line of local server based extension apps (web apps that run on your own computer as the server) that software manufacturers have been coming out with lately. Connects to your Mac so you can access to everything Colloquy is connected to. Even if your WiFi or EDGE network drops, you will get all the messages once the network comes back. Use all your favorite Colloquy scripts from your phone using the same IRC commands. Specially designed interface to match the iPhone and iPod touch with landscape support. There is a demo of the extension app available for you to try as well. Colloquy is free OSX software.

To Install:
Get the latest version of Colloquy.
Download the beta Web Interface plugin.
Install the plugin in: ~/Library/Application Support/Colloquy/PlugIns
Create a new password that will be used to login from Mobile Safari. Type the following command in Terminal.app with your password at the end:
defaults write info.colloquy WebInterfacePassword <>
Open or relaunch Colloquy.
Visit http://yourip:6667 in Mobile Safari on your iPhone or iPod touch.
Enter the password you created earlier

Get it here