Thanks to the industrious folks in PRC, iCosta introduces an additional input method for Jailbroken iPhone owners.
Even from firmware 1.0.6 the iPhone was already capable of supporting Chinese text but unfortunately even until now, that support is only to the extent of displaying text. Not input.
Add http://iphone.freecoder.org/rep into the list of Sources in your Installer app and iCosta becomes available for install. iCosta is touted to support all firmware versions and is a great solution for the Chinese writing iPhone owners who cannot wait for Apple Inc to provide this function natively.
After adding the source, select the correct version of iCosta fitting your iPhone’s firmware from the Localization menu and you’re typing Chinese on your phone seconds later!