How to add pinyin input to Sony Ericsson cellphone?

I finally broke down yesterday and had to purchase a new phone. My old Motorola that came free with my contract lasted me 2 years, but was finally wearing out. The buttons did not press easily, the battery would die mid conversation (despite being charged) and it was time to throw in the towel.

The problem is - I had a hard time finding a phone I liked that had Pin Ying on it. I’m an impatient shopper and finally settled on a Sony Ericsson phone, but am still annoyed that it does not have Pin Ying. They said someone, somewhere can put it on there, but they have no clue where. Sony Ericsson store said the same thing. Any advice on where to find that?