Google releases a nifty command line interface to Calendar, Blogger,
Picasa, Contacts, Docs, and more:

http://code.google.com/p/googlecl/wiki/ExampleScripts

Just brainstorming here, because GCal is my main calendaring app: we
could make a todo.txt add-on that will add a task to your Google
Calendar on a given date in the same command as adding it to todo.txt.
Should be an easy one! If I have a little time this weekend I may take
a crack at it.

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