Handwriting Input method is a very good function provided as default by Mac.
Below is how they are activated by user:
1. Check the installation of your trackpad.
If no trackpad detected, in Setting->Langauge & Text, the screen should be looked like the picture below.
Noted that there is no choice available about the Handwriting Input Style.
2. If you installed the trackpad correctly,the same dialog box should look like this one instead.
Just check the box next to the Handwriting Style.
Notice how the HotKey change to provide hint of how to activate.
The HotKey means: control+shift+space
Finally, the diagram below provide supplementary information of how you can find the option to install the trackpad.
You must have trackpad installed to activate Handwriting Input Style.
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