Macbook 2010 with OS X 10.9 - "Dangling Thumbs" issue while typing
there used to be an option for it as seen in this article: http://support.apple.com/kb/HT3608?viewlocale=en_US&amp;locale=en_US
If you have a mac running mountain lion or below this still works.
There is still an option to disable tap to click in system preferences/trackpad but that disables it even when you are not typing.