InetTools IRC - very good IRC client for your phone. Maybe the most advanced one. Thanks to the author XAOC for his effords in the development.
The program will run in Russian language. If you wish you can very easily recompile it in English (or any other language) by editing the language.dat file (you can extract it from the .jar archive with winrar, lzarc or other dearchivator). The translation will be self explanatory for you (even if you do not know Russian at all). We will leave you to check that yourself and ensure :)
* Screenshots from the website mobilepack.org
The link for download is directly JAR file and this is MIDP2.0 version that runs on Motorola E398 and ROKR E1