If you’re using GNU/Linux and you are looking for an easy-to-configure input application, gcin is it.
In addition to it being available where the above site lists it, it is also available in the Ubuntu repositories (Dapper, for certain).
I tried xcin, scim, and skim, but I could never get them configured properly so as to allow me to use them across applications (Konqueror to Firefox to other QT and GTK applications) despite having the option turned on in the configuration. (I admit that it could be ignorance on my part.)
But, gcin is simple, powerful, and it configures easily by itself. It works across applications. Additionally, you don’t have to start from a terminal or anything. Just right-click > select input method > gcin, then Ctrl + Space to get started. It even “guesses” the next character(s) while you’re typing, like the Windows input method.
(Oh, I’m using it under Mepis 6.0 RC2.)
Of course, be sure to have the zh_TW locale installed and generated…
Let us know about any tricks or configuration magic you might work out.
NOTE: Get Hanzi master while you’re at it.