colloQ is an improved IRC client for the iPhone, based upon mColloquy.
Release notes:
After a hiatus from coding, I recently got back to it and fixed the extended ASCII characters bug! This fix is so important that I decided not to spend time with any more fixes or enhancements and release it right away. It is available on Cydia now, and will be available on Installer very soon. http://code.google.com/p/colloq/