One of the new refinements released with Snow Leopard, was Chinese character input. This does come standard with any install of Snow Leopard, but isn’t enabled – you need to take a couple further steps to have it functioning and ready.
First, you’ll need to make sure you have one of Apple’s laptops that is equipped with the glass trackpad (the one without any buttons), and running 10.6 or later.
Second, open your system preferences, and choose Language & Text option under ‘Personal’.
Under Language & Text, choose the ‘Input Sources’ tab, then on the list on the left hand side, scroll down and choose either Chinese – Simplified or Chinese – Traditional. You’ll notice that when you do this, the right hand side of the preferences window will show “Show/Hide Trackpad Handwriting Control + Shift + Space” no longer greyed out. This is the key combination you’ll use to toggle the handwriting input dialog.
After doing this, you can toggle the control window/handwriting input dialog by holding Control + Shift and then tapping the space bar. Once it comes up, you will write with your fingers on the trackpad. On the right hand corner of the dialog, you’ll see the computers best 4 approximations of what it is you’re trying to input, and you’ll choose accordingly. Since the trackpad is now dedicated to your handwritten input, you’ll have to imagine that the far right of the area is divided into 4 squares, and tapping either on the top, slightly high, slightly low, or on the bottom, will choose one of those four character approximations.
This same process is available on desktop Macs as well, but you need a third part input device.