You could try searching a T9 keyboard in the android market, I have used Better Keyboard or you can install the HTC_IME keyboard which is available from XDA forums, which may sound complicated but it really isnt.
First off, download a file manager from the android market on your phone - Astro or Linda are both good and free.
If you then click the link in post number 2 on this thread http://forum.xda-developers.com/showthread.php?t=930259 to download the keyboard to your PC. Then unzip it, but don't try and open it. Copy it across to a folder on your SD card, I named mine HTC - not exactly original but I know where to find it.
On your phone using your File Manager (Astro/Linda) find the HTC file and open it. Tap on the HTC_IME_hi22 file and you should get a pop up asking you to browse file or Open App Manager (Astro) select app manager and select install.
Nearly there now so bear with me.... from your home screen press Menu>Settings>Language and Keyboard and tick HTC_IME keyboard, go to the HTC_IME settings underneath this and in keyboard types you can select phone keypad but the qwerty keyboard is better than the normal phone one too - you can also set up Gestures so that if you swipe right you can cycle the keyboard between T9 and qwerty. Now open up your text app and start a new message. Tap the text input box which will bring up your current keyboard, but then long press on the text input box and you will get a pop up that offers Input Method, select this and then select HTC_IME.
Your last option is to follow the long press advice as above and select Chinese keyboard if you have the option and that gives you a T9 keypad (but I still prefer the HTC_IME keyboard - got it on all my phones in various forms, X8, X10 and Neo.
