During today's Language Enhancements webcast, I received a question about what's going on with Visual Basic for Applications (VBA) - we briefly touched upon VBA and some of the other Office automation/customization tools.  To help you out, I did a little research to find the resources that you can use to fill your brain:

VBA (Visual Basic for Applications) is a scripting language supported in several Office applications.

VSTO (Visual Studio Tools for Office) is a Visual Studio enhancement to support .NET managed code development for Word and Excel documents and Outlook Add-Ins.

VSTA (Visual Studio Tools for Applications) is a framework for adding scripting support to your own custom applications.

Which of these do you use in your development work?  How do you use these tools?