1*. on ur menu bar, click on the US flag.

2*. select "open international ".

3. u should see the international preferences. click on "input menu" tab.

4. scroll down until u see "simplified chinese ". turn it on and "ITABC" (hanyu pinyin) shld be enabled as a default option.

5. typing it out.... type "hanyupinyin" without spaces...

then press space

then press 1 (pinyin has only 1 match)

note 1: to change between input methods, until access the US flag above again or set a shortcut to it in international preferences page.
note 2: the key to execute a search of characters is space. enter does not work for some reason. and for the tone, i dunno how to set also, i just scroll thru all of them. since the characters i use are quite common, it wasn't a problem actually.

and there are many many languages pre-installed in the mac os x for u to play with.
* the alternative to steps 1 and 2 is apple icon -> system preferences -> international.
